We had to replace all floor coverings (all rooms had cigarette burns and permeated smoke odor into the carpet and pad, had to clean-seal-repaint all walls and ceilings, deep clean all cabinetry and every surface in the unit.  

Well J Scott maybe some of us think money spent on keeping Americans alive is a little more damn important than money spent on pig odor research.

from my perspective as a NMLS licensed Mortgage banker... is D F won't get repealed as a whole.the govmit spent a billion dollars creating NMLS  all of us mortgage bankers or RMLO's are now registered in one federal system.. it would create massive issues between the states and feds how we operate.DF from someone who actually works in the system ( me) is a pain for sure.. we have to use this super complicated website called NMLS .. we have to do reporting quarterly that is over the top and bigger shops no doubt had to hire a compliance person as it would become a full time job.. little guys like me we just grumble  but have to comply.Wall st will dictate rates  LTVs and risk.. along with bond buyers ..

Tenant agrees to pay $50.00 per day to ionize the premises to remove any unwanted odors, and $5.00 for each cigarette butt found on premises."

They attenuate noise and cover (dog pee odor soaked on subfloor).

I tried contacting a couple of deep-cleaning companies and both turned me down for cleaning as they feared potential liability with it being fire damage and the odor remaining.

We do not allow cats period because of the odor damage they can do down to the sub-floor if they spray carpet and padding.

I agree with what @Travis Sperrsuggested with the floors being painted to cover pet odor.

My tenants had multiple pet cats which had left a real strong smell and  odor in the house.

It removes odors from smoking, pets, food, teenage boys, etc.I purchased an apartment complex and one of the units had smokers in it for over 30 years.