Search past threads on this, some mention a chemical, TDP.Also have all the vents mechanically cleaned/brushed.Ozone generator in there for a couple of days post cleanup.

So, I didn't have to take any major steps to remedy the issue, but I am interested to hear others' tips.My real estate agent said that there is some chemical that you can put on the walls and literally watch the nicotine run out of the walls (don't recall the name).

It dumps forever chemicals into the water, rats chew on them, and I find it difficult to believe that PEX will last more than 25 years.  

I have learned to get a cheap maintenance person and have them buy the good chemicals from A1 Able and spray it for you.

I was able to politely get out of that call in only 20 minutes, I consider that a win.I have no evidence but I suspect some recreational chemicals might have been involved.  

Chemicals are probably about $10 a month.It's minimal expense.

There are chemicals that you can spray on them to eliminate this or replace the stained subfloor plywood.

It can crush lines and collapse the tops of tanks.5) Do not use chemical drain cleaners (Draino, etc.), they quickly deteriorate the concrete components and cause failure.6) Adding various enzymes and bacteria is up for debate.  

Tenant shall only use a plunger to attempt to fix a slow or stopped drain, and not pour chemical or other drain cleaners into any stopped or slow drains.Tenant shall also be responsible for any plumbing system freeze-ups occasioned by Tenant’s negligence. 

Cat urine consists of mainly three chemical parts.