I just moved into a very old but, for many reasons, desirable apartment, EXCEPT for the smell coming from under the kitchen sink and, seemingly, also the dishwasher. I have already used two dishwasher "cleaners" on it.

It is HUD housing and I have complained to the management. From management to maintenance, they all deny being able to smell anything. At first I thought they all must need their olfactory systems inspected by a medical professional; but, I think they just need a lie detector tests. They won't admit anything because then they would be obligated to do something about it. I am worried about the health concerns. The smell is usually of rotting garbage sometimes with an ammonia component. I think it may be coming from the apartment adjoining mine because I also smell it when they smoke cigarettes. Anyway, I am thinking that the wall between the apartments is seriously compromised if I am smelling cigarette smoke in my apartment from the apartment next door.

What can I do? I have already offered to spend my money investigating the problem and fixing it if it is not too costly. The management will not allow me to do this. I guess by giving their permission, it would be tantamount to admitting a problem and that is the last thing they want to do. Also, it is a very small town and I have already been turned down by two people who could investigate the problem but say they won't without Housing Authority approval.

Is there something I could paint onto the wall and the back of the cabinets that adjoins the apartment next door that would create a seal and prevent odors from coming into my apartment?

This is something you are going to have to live with... because it's a reality of most apartment buildings due to how pipes and wiring are run when it was built.. They aren't going to spend large sums of money trying to fix something that basically can't be fixed to satisfy a renter.

Unless you can show a leaking drain pipe... ( which would be on the drain side of the P-trap.. not the sink side... most likely on top) where sewer gas can escape and yet leak no water.

Sorry... they will fix what's really broke... but they aren't going to jump through hoops to deal with what are only annoyances.

I know that not what you want to hear... but that's the reality... they have to turn a profit... and in many cases rules and regulations (rent control, vouchers etc) make that difficult and approaching impossible. And in those cases they will do as little as they absolutely have to do.