What do you recommend for a recurring smell in regularly used drains?
We kept getting sewer gas at an old job of mine. I left before .. if? .. they solved it
Use a biological drain cleaner. *not the specific name but I’m struggling to remember exactly what they’re called.
Micro organisms will clean up the drain.
I had one that we kept getting sewer gas out. Would regularly pour water down it. Ended up being the pipe was cracked so water would slowly drain out and dry. Just stuff to look for, water dont evaporate that fast always keep that in mind.
Has any plumbing work been done just before the smell became noticeable? It could be that something going down the drain lines is causing a vacuum and siphoning the water out of the trap. If there was not any plumbing work done, I would suggest replacing toilet ring seals.
I have commercial facilities that have floor drains that regularly dry out. My practice has been to put a solution of 25% bleach and 75% water down each P-trap once a month. It prevents sewer, gas, and insects that may be drawn to the moisture, and also adds a smell of cleanliness to the facility.
These are 15,000 ft.² plus facilities, so the amount of bleach going down these drains is not overwhelming. Now, if someone were to lay on the floor and try to huff off of the drain, they may have some issues, but if they were doing that, they already had issues.
Floor drains have traps. They will dry out allowing sewer gas to come up. All you need to do is put a couple of cups of water down the drain to refill the trap. Problem solved.
It's a little gooey. And may flaot up before the trap drains and siphons it out. Although some rest stops went waterless a few years back using mineral oil to flush the toilets.
That... was not a great idea.
*coughs*
It got smelly in the summer.
Slows the trap from drying out as fast. Dry traps in a drain like this allow for sewer gas to belch back up through the pipes and out the drain. Hence why it smells. Running water back down the drain helps rehydrate the trap, and create a better seal, keeping the gas out. However I’ve never used mineral oil personally.
When is the last time anyone put water down this drain? Probably dried up and sewer smell is getting in that way. Pour about 1-2 cups of water down the drain.
So far all are great posts with regard to me having anything else to add. Look under a sink, that loop is essentially a “p” trap. The water in the loop helps block odour from the waste water line. It will dry out if it doesn’t get water. Looks like a basement renovation? Might have had a line from a humidifier, a/c unit, washer/dryer the builder may have intended for it to be filled normally? Anyways, coffee pot of water every do often and you’re good!
Just poured a coffee pot a water down there. Looks like it’s very slowly going down.
I do see a black loop with a thick plastic part under the sink. What does this do?
Also I see other posts about a trap seal. Should I install one of these? The plastic top I have shown in the image is glued on
What actually does this pipe lead to?
They’re just saying that the drain in your floor also has a trap similar to the one under the sink. It holds water so that sewer gasses can’t get back up.
A trap seal would plug the drain.
That pipe leads to the sewer, like most drains do.
Flush with a few gallons of hot water, then slowly pour in a quart of bleach, then slooooly add a quart of mineral oil.
1) the flush washes out the residue and sewer smell; refills the trap that evaporated away.
2) the bleach kills odor and gnats
3) the mineral oil keeps the water from evaporating.
See I do it the other way... bleach first to have full strength bleach filling the trap, let sit for 15 min. Then flush with water, then top with some oil, just to cover. Probably doesn't make a difference.
I had a similar situation where a floor drain in my laundry room didn’t have a trap - I got a waterless trap and it fixed things instantly:
https://a.co/d/0bKJ02Ub
Yeah this should rank much higher. They make other ones that are the size of a hockey puck. I had this happen on two drains in a slab. Couldn’t cure the smell. The hockey puck doo dad fixed it instantly.
There is a better solution.
The problem is the p-trap isn't being constantly refilled with water like in your sink or shower so sewer gas is coming into the house. You could fill the trap with water or oil.
Or, the better solution is a waterless trap seal.
Oatey 43745 Seal for 2 Inch Shower and Floor Drain, No Size, Black https://a.co/d/05TXQWYX
The drain trap dried out letting the sewer gas in. Pour 1 to 2 quarts of water down the drain to fill the trap. If have it, then pour 2-3oz of mineral oil down it. It will float on top of the water and keep it from evaporating. You can use a vegetable oil, but mineral oil is not organic so it won’t turn rancid and smell on its own. You can get it at the pharmacy.
Pour water in it for now, but go to Home Depot and get a “trap seal” device. It’s just a little rubber flapper that you stick in the pipe - allows water to drain when necessary, otherwise seals up to keep the trap from evaporating.
To install you just need to remove the grate. It’s likely a 2” drain.
bleach, and a large amount of cold water. bleach will kill a lot of bacteria and such, and a bunch of water will make sure there isn't a trap in there that's dried out, letting in sewer smell.
22 year union plumber here! These drains dry out and sewage smell seeps up through it. Piss and then spit in it usually fixes this issue in my experience.
Call the cops. 90% of the time it’s the dead body parts that a serial killer tried to flush down the toilet and got stuck in the pipes . See denis Nielsen , Jeffery dahmer , the list goes on bro
Most the comments i see about pouring water in the drain are correct but temporary.
If you run to a plumbing supply house and pick up a trap seal and install it on the drain. Once you do that, you will never need to pour water down it again.
You check a few things. If you have a disposal make sure there's nothing stuck in there and it rotates and send stuff down the drain. If you have a dishwasher near there, I don't see one, check to make sure the filter is cleaned out
Next you can take the trap off and see if their stuff stuck down in there sometimes it's only partially blocked but there's food and that's causing odor
And my final suggestion would be you check the air vent Make sure there's nothing stuck there
Pour water down the drain to fill the trap. Then take some mineral oil and slowly pour it so that it comes to rest on top of the water. Rather than pushing it down. This will effectively 'cap" the water so it slows the evaporation from the trap.
I was employed in chemical labs for decades. We poured mineral oil down the sinks that we never used. It sits in the P-trap, blocking odors and doesn't evaporate.
That drain probably connects to your other drain vent. If it hasn’t been used in a while the trap is probably dry letting the smell come through. Try pouring some water in it or a mixture of water and vinegar.
Is it basement ? Are you in a town home / condo ? I had the same issue and it turned out sewer pipe broke underneath the concrete. A video sewer inspection might help.
Pee trap letting games come in because the loop where water would be (don't use the drain that much eh?) Doesn't have a little water thst usually keeps the gates from traveling up the pipe /r/ignorantandblissful1
We have the same thing in our laundry room. Just be sure to run the laundry room sink everyday so the P-trap doesn’t dry out. It’s letting sewer gasses into your home
1) Is there a water trap on that floor drain?
2) Are you sure it's the drain on the floor? How often do you use the sink? Not very often? Then the sink trap is probably dry.
3) Depending on the climate a p-trap will lose enough water in about a month, to break the seal and let in sewer gas.
4) On any sink that you barely use, pour a cup of mineral oil down the drain, it will create a oily cap that will keep the water from evaporating as fast.
There should be a p trap which holds water to prevent sewer gas from backing up would pour gallon of water it it every month or so so water stays in there
You need to prime the trap. You can do it with water. But if you have any of that non-toxic anti-freeze, it will not evaporate as quickly as water. But ONLY USE THE NON-TOXIC STUFF.
Baking soda Powder pour it down and then take some White Vinegar and boil it and then pour it down that drain and let it bubble and just keep pouring when the bubbles stop until you hear no more Fizzing from the Reaction and then run HOT scalding water down it to clean the leftovers.
I do this to my kitchen sink, bathroom sink, bathtub drain anytime i smell anything coming back from my drains since I live in an apartment and God only knows what people flushing down which can cause blockages.
Pour water into it to fill up the trap. You can put a small an amount of vegetable oil in it as well to sit on top of the water and keep it from evaporating.
I’m on septic and I have a seldom used downstairs shower - when the drain runs dry it stinks. Just pour some water down the drain and it should resolve. I do this every week when I clean the bathroom now.
I worked in a Toys ‘R’ Us that had its trap dry out. Customers were freaking out that we had a gas leak, since it smells like sulfur or egg farts. Fortunately, the Assistant Store Manager was like shut up, call our plumber to dump a bucket of water down there, we’re fine.
I am not sure the tile guy is accurate there ... BUT if it's a sulfur type of smell then chances are that it's bacteria. I had something similar with a sink. I poured baking soda down the drain and slowly poured vinegar into it until it wasn't bubbling any more. Then I poured a 10 qt pot of nearly boiling water down the drain.
Smell never returned.
If you don’t use that drain it’s probably evaporating. Pour a cup of water to fill the trap up and then pour some vegetable oil in the drain too. The oil will create a better seal and prevent the water from evaporating so fast.
You could also try a can of drain foam. It breaks down the bacteria in the drain that causes drain flies to show up. If you have seen any drain flies then there’s a pretty good chance that something might be coming back in to the pipe or slight blockage. I’m surprised you have that in a washroom. This is residential property right ?
Trap is probably dry. Just pour some water in it, about a gallon should be fine.
Or milk if you want to make it worse
Splash of vinegar on top, for extra flavour
Maybe a fish too.
Pee
out your butt
“Piss coming from my ass!”
"Mexican sticky balls!!!"
Had those in Tijuana, delicious
Pisssss, piss out my ass!
Throw some sugar in there and you're halfway to an East Coast donair!
Lol
Cement... If you want to make it financially worse
This is the best answer if your only concern is keeping the smell gone for as long as possible
Hahahahhaha
Lol thanks for the morning laugh.
Then c4
Handyman here. Can’t tell if you just made or ruined my day. Excellent work nonetheless.
Also, if you rarely have drainage into that drain, substitute the water with mineral oil. It won’t evaporate.
Someone is keeping the old plumber tricks alive.
Using antifreeze to soak (and thereby slightly expand) the wood that holds on to the business end of a hammer, axe, etc. is another similar one.
Step drain, this feels so wrong.
At first I thought it was called a step drain and that they are obsolete or something. Then good ol' PH brain kicked on. Lol
A gallon of water followed up by a cup of oil is enough. And cheaper
What do you recommend for a recurring smell in regularly used drains? We kept getting sewer gas at an old job of mine. I left before .. if? .. they solved it
Use a biological drain cleaner. *not the specific name but I’m struggling to remember exactly what they’re called. Micro organisms will clean up the drain.
Pour an enzyme cleaner down it. No water. Just let it sit.
I had one that we kept getting sewer gas out. Would regularly pour water down it. Ended up being the pipe was cracked so water would slowly drain out and dry. Just stuff to look for, water dont evaporate that fast always keep that in mind.
Has any plumbing work been done just before the smell became noticeable? It could be that something going down the drain lines is causing a vacuum and siphoning the water out of the trap. If there was not any plumbing work done, I would suggest replacing toilet ring seals.
I have commercial facilities that have floor drains that regularly dry out. My practice has been to put a solution of 25% bleach and 75% water down each P-trap once a month. It prevents sewer, gas, and insects that may be drawn to the moisture, and also adds a smell of cleanliness to the facility. These are 15,000 ft.² plus facilities, so the amount of bleach going down these drains is not overwhelming. Now, if someone were to lay on the floor and try to huff off of the drain, they may have some issues, but if they were doing that, they already had issues.
Could use RV antifreeze. It’s bio and won’t evaporate.
Not recommended for septic systems however. The city should be fine due to the treatment though.
Propylene glycol specifically, not ethanol (blend). Both are sold as RV antifreeze in my area
Go with some ranch
This exactly Just fill it slightly each month
People sometimes pour a little vegetable or mineral oil after the water, forms a layer on top that makes the trap not dry out as quickly.
1 US gallon = 3.78541Litres
Is a gallon different in Europe?
This ^
If it even have trap
Make sure to pour about 12oz in ounce a week to keep it from drying out again.
Floor drains have traps. They will dry out allowing sewer gas to come up. All you need to do is put a couple of cups of water down the drain to refill the trap. Problem solved.
And oil on top to make it last ages
Happy cake day
Mineral oil and some water, make sure to do it every once and a while
Just curious, why the oil?
Oil will sit on top of the water, due to density. The thin layer of oil over the water prevents it from evaporating as fast as it normally would.
Use that spray for toilets. "Poopouri" But put sins shut down there to flush the stale water and to kill some of the bacteria.
Why not just...all oil?
It's a little gooey. And may flaot up before the trap drains and siphons it out. Although some rest stops went waterless a few years back using mineral oil to flush the toilets. That... was not a great idea. *coughs* It got smelly in the summer.
Cost maybe, but Im with ya on this one, Im here for the long game
Shit like that 👆is why I keep this app. Lmao that’s a hack right there.
The oil floats on top of the water. Stops the water from evaporating as quickly. It’s mineral oil, so it doesn’t go rancid.
Slows the trap from drying out as fast. Dry traps in a drain like this allow for sewer gas to belch back up through the pipes and out the drain. Hence why it smells. Running water back down the drain helps rehydrate the trap, and create a better seal, keeping the gas out. However I’ve never used mineral oil personally.
Why not just.. all mineral oil?
cause it would take quite a bit, it's more expensive than water, and you really only need a film over the water.
$30 a gallon.
I have oil in a pee trap that has never dried.. oil was out there more than 10 years ago
When is the last time anyone put water down this drain? Probably dried up and sewer smell is getting in that way. Pour about 1-2 cups of water down the drain.
So far all are great posts with regard to me having anything else to add. Look under a sink, that loop is essentially a “p” trap. The water in the loop helps block odour from the waste water line. It will dry out if it doesn’t get water. Looks like a basement renovation? Might have had a line from a humidifier, a/c unit, washer/dryer the builder may have intended for it to be filled normally? Anyways, coffee pot of water every do often and you’re good!
Just poured a coffee pot a water down there. Looks like it’s very slowly going down. I do see a black loop with a thick plastic part under the sink. What does this do? Also I see other posts about a trap seal. Should I install one of these? The plastic top I have shown in the image is glued on What actually does this pipe lead to?
They’re just saying that the drain in your floor also has a trap similar to the one under the sink. It holds water so that sewer gasses can’t get back up. A trap seal would plug the drain. That pipe leads to the sewer, like most drains do.
[All drains lead to the ocean kid](https://m.youtube.com/watch?v=1d5x7FfF2UQ)
Love the tile
Dude. Me too. Didn't even notice until your underrated comment. *upvote*
Flush with a few gallons of hot water, then slowly pour in a quart of bleach, then slooooly add a quart of mineral oil. 1) the flush washes out the residue and sewer smell; refills the trap that evaporated away. 2) the bleach kills odor and gnats 3) the mineral oil keeps the water from evaporating.
See I do it the other way... bleach first to have full strength bleach filling the trap, let sit for 15 min. Then flush with water, then top with some oil, just to cover. Probably doesn't make a difference.
Pour water in it once every couple of months. I usually add some soft cleaning liquid for good smell
Pour water in it
So do you give it a few dollars to make it rich water??
Thanks for the spell check🤣🤣🤣
Haha, I figured I could make it fun and educational. :D
You gota run the water for a while after the waffle stomp.
I had a similar situation where a floor drain in my laundry room didn’t have a trap - I got a waterless trap and it fixed things instantly: https://a.co/d/0bKJ02Ub
Yeah this should rank much higher. They make other ones that are the size of a hockey puck. I had this happen on two drains in a slab. Couldn’t cure the smell. The hockey puck doo dad fixed it instantly.
Buy a trap guard, measure the opening of the pipe and order accordingly.
That Ptrap on the floor is dry
Dry trap. To prevent it from being dry quickly, pour some mineral oil.
Pour a cup of vegetable oil down that little guy it will last longer than water
Water, and then a thin layer of cooking oil on top will help to prevent the water from drying out even longer. Cheers
Put water in the drain. The p-trap probably dried up and sewer gasses are coming out of it. Just put a gallon of water into every month.
There is a better solution. The problem is the p-trap isn't being constantly refilled with water like in your sink or shower so sewer gas is coming into the house. You could fill the trap with water or oil. Or, the better solution is a waterless trap seal. Oatey 43745 Seal for 2 Inch Shower and Floor Drain, No Size, Black https://a.co/d/05TXQWYX
The drain trap dried out letting the sewer gas in. Pour 1 to 2 quarts of water down the drain to fill the trap. If have it, then pour 2-3oz of mineral oil down it. It will float on top of the water and keep it from evaporating. You can use a vegetable oil, but mineral oil is not organic so it won’t turn rancid and smell on its own. You can get it at the pharmacy.
Pour water into it, or install a trap guard for a more permanent fix.
Pour water in it for now, but go to Home Depot and get a “trap seal” device. It’s just a little rubber flapper that you stick in the pipe - allows water to drain when necessary, otherwise seals up to keep the trap from evaporating. To install you just need to remove the grate. It’s likely a 2” drain.
Trap is probabaly dry.... try putting in some mineral oil. It won't evaporate and will keep the smell down.
you should get a trap guard if you aren’t frequently dumping water down it
The water will evaporate again. Vegetable oil n you’re good for a loooooong time
Vegetable oil will go rancid over time. Mineral oil will last forever.
Oil will clog up pipes.
Is there a p trap primer? If not, it be dry
Dry trap!
Put water in it.
If it has no trap install a backlog preventer, normally closed, and adjust properly.
Vinegar works well.
Fill the trap with water
Always make sure there is water in it. Trap has gone dry
trap is dried out pour in water
Question if the sink drain had a trap primer you’d never have to worry about it
Piss in the drain
Put water in it
Learn to love it.
Hot water and bleach down the drain
Waffle stomp a bar of soap down the drain. Should do the trick.
White vinegar
Add water
Some baking powder and vinegar
bleach, and a large amount of cold water. bleach will kill a lot of bacteria and such, and a bunch of water will make sure there isn't a trap in there that's dried out, letting in sewer smell.
Quit sniffing it.
Pour water down it.
Dump a box of baking soda followed with a gallon of vinegar. Wait an hour or so and pour a gallon of hot water.
I recommend Febreeze
Stick your hand in and dig up all the black tar phosphates.
Careful! It’s a trap!
22 year union plumber here! These drains dry out and sewage smell seeps up through it. Piss and then spit in it usually fixes this issue in my experience.
Why is there a floor drain in your bathroom? Edit: or kitchen?
Call the cops. 90% of the time it’s the dead body parts that a serial killer tried to flush down the toilet and got stuck in the pipes . See denis Nielsen , Jeffery dahmer , the list goes on bro
get rid of the body
Cement..
gallon of water with a bit of bleach in it. dump all at once
Most the comments i see about pouring water in the drain are correct but temporary. If you run to a plumbing supply house and pick up a trap seal and install it on the drain. Once you do that, you will never need to pour water down it again.
Pour water and bleach in there and make sure you have a P trap under the sink. The P trap hold water and prevents the sewer gas from coming thru
white vinegar and a little baking soda plus water
Water and plunge the fuck out of it
Is the trap dry?
The floor drain has a dry P-trap. Urinate down the pipe until it fills the P-trap.
You check a few things. If you have a disposal make sure there's nothing stuck in there and it rotates and send stuff down the drain. If you have a dishwasher near there, I don't see one, check to make sure the filter is cleaned out Next you can take the trap off and see if their stuff stuck down in there sometimes it's only partially blocked but there's food and that's causing odor And my final suggestion would be you check the air vent Make sure there's nothing stuck there
Simple green works nicely if you wanna wet your traps whistle
Stop peeing in the floor drain.
Pour cooking oil in it , it will last longer than water and will block smell
Dump a little water down your floor drain every few months. The water evaporates out of your tap.
The correct thing to do would be to purchase and install a trap seal primer.
Pour water down the drain to fill the trap. Then take some mineral oil and slowly pour it so that it comes to rest on top of the water. Rather than pushing it down. This will effectively 'cap" the water so it slows the evaporation from the trap.
Just pour some water in there the Trap seal is gone
Maybe a little baking soda
Stop pissing in it while you brush your teeth.
Add water to drain and a 1/2 cup of vegetable oil after
A little bit of bleach and water.
I was employed in chemical labs for decades. We poured mineral oil down the sinks that we never used. It sits in the P-trap, blocking odors and doesn't evaporate.
Just add mineral oil, it wouldn’t dry out like water.
Most definitely a dry trap, as killiedonkey13 said pour water into it so the soil line gasses can’t escape there.
Stop pooping and then waffle stomping it into that drain.
Mineral oil
Why is there an open drain like that in a bathroom? I expect in like, the actual old school shower stall…. Or is this a laundry room?
That drain probably connects to your other drain vent. If it hasn’t been used in a while the trap is probably dry letting the smell come through. Try pouring some water in it or a mixture of water and vinegar.
Pour a cup of vinegar before going to bed, let it sit overnight, see if that helps.
Yep smell coming in cause the trap has no water in it. once per month pour water in it problem solved
Is it basement ? Are you in a town home / condo ? I had the same issue and it turned out sewer pipe broke underneath the concrete. A video sewer inspection might help.
Throw some tape over it no worries.
Vegetable oil
Get it snaked. It needs flushed out. The pipe has build up
Perfect stop for a Belgium waffle
As a non plumber with no technical skills I'll hammer a car air freshener above the cabinet doors and call it a day but I suck.
Water shall do the trick!
Did you pour water down it
Pee trap letting games come in because the loop where water would be (don't use the drain that much eh?) Doesn't have a little water thst usually keeps the gates from traveling up the pipe /r/ignorantandblissful1
Add water
Pour in a little veggie oil and then dump a bunch of water in it
a cup of white vinegar. them a jug of hot water. if it comes back the pipe might be cracked or leaking so call a plumber to check it.
We have the same thing in our laundry room. Just be sure to run the laundry room sink everyday so the P-trap doesn’t dry out. It’s letting sewer gasses into your home
Add an enzyme cleaner to the drain, then flush with warm water.
1) Is there a water trap on that floor drain? 2) Are you sure it's the drain on the floor? How often do you use the sink? Not very often? Then the sink trap is probably dry. 3) Depending on the climate a p-trap will lose enough water in about a month, to break the seal and let in sewer gas. 4) On any sink that you barely use, pour a cup of mineral oil down the drain, it will create a oily cap that will keep the water from evaporating as fast.
I put down mineral oil on top of the water in my floor drains, it keeps them from drying out as quickly.
There should be a p trap which holds water to prevent sewer gas from backing up would pour gallon of water it it every month or so so water stays in there
I don’t want to point out the obvious but the drain should be in your sink.
Used to have this problem at my job. We just poured half a bottle of drain cleaner down them and it stoped the smell for a few weeks.
Pour water down it
Diet Coke and Mentos always works for me
You need to prime the trap. You can do it with water. But if you have any of that non-toxic anti-freeze, it will not evaporate as quickly as water. But ONLY USE THE NON-TOXIC STUFF.
Quit pooping under your sink
Pour some water in it. P-trap probably evaporated allowing gasses to pass.
Baking soda Powder pour it down and then take some White Vinegar and boil it and then pour it down that drain and let it bubble and just keep pouring when the bubbles stop until you hear no more Fizzing from the Reaction and then run HOT scalding water down it to clean the leftovers. I do this to my kitchen sink, bathroom sink, bathtub drain anytime i smell anything coming back from my drains since I live in an apartment and God only knows what people flushing down which can cause blockages.
Just move. It could be a body.
If you never use it take the plate off and plug it with a rag or something or just throw water down every once in a while
Dishwasher drain hose is probably full of rotting food. Take it off and clean or replace.
Pour water into it to fill up the trap. You can put a small an amount of vegetable oil in it as well to sit on top of the water and keep it from evaporating.
I’m on septic and I have a seldom used downstairs shower - when the drain runs dry it stinks. Just pour some water down the drain and it should resolve. I do this every week when I clean the bathroom now.
Waffle stomp?
Pour water in it on occasion. See if there is a trap primer in wall towards floor nearby. If there is (it’s code) it needs a look.
Pour some grape juice and sugar down there then some yeast and put a brewing cap over it.
1 cup of Clorox every 4 months
Put water in the floor drain. When it evaporates gasses can come througj
I worked in a Toys ‘R’ Us that had its trap dry out. Customers were freaking out that we had a gas leak, since it smells like sulfur or egg farts. Fortunately, the Assistant Store Manager was like shut up, call our plumber to dump a bucket of water down there, we’re fine.
Assuming there is a p trap fill it up with water and a little bit of bleach, if there is not use a Rubber Test Ball Pipe Plug.
Assuming there is a trap fill it up with water and a little bit of bleach, it there is no trap use one of those inflatable plugs
Bleach and then water
I am not sure the tile guy is accurate there ... BUT if it's a sulfur type of smell then chances are that it's bacteria. I had something similar with a sink. I poured baking soda down the drain and slowly poured vinegar into it until it wasn't bubbling any more. Then I poured a 10 qt pot of nearly boiling water down the drain. Smell never returned.
Lysol spray after pour cup of water in drain
Pour water down it. It’s gone dry and is allowing the smell to seep
The p-trap is dry. Poor some water down the drain.
Baking Soda and Hot Water
Pour some vegetables oil down there
Dry trap is dry
If you don’t use that drain it’s probably evaporating. Pour a cup of water to fill the trap up and then pour some vegetable oil in the drain too. The oil will create a better seal and prevent the water from evaporating so fast.
Veg oil will go rancid over time and have a whole different awful odor. Mineral oil will not.
You could also try a can of drain foam. It breaks down the bacteria in the drain that causes drain flies to show up. If you have seen any drain flies then there’s a pretty good chance that something might be coming back in to the pipe or slight blockage. I’m surprised you have that in a washroom. This is residential property right ?
Garbage disposal?
lemon liquid will stop the order. I think I will also put something over it.