I haven't had much success with ozone generator as they only clean the air and not the enzymes themselves.

It is an enzyme that actually eats the urine. 

I also like the enzymes (Nature's Miracle for actual pet vomit)...

I don't remember what it was called, but when I cleaned carpets years ago, we used an enzyme on the slab (I think it was called Microban)after removing the carpet and padding.

Cat is a maybe, maybe not.I suggest that you give the stains a good soak with an enzyme cleaner, let it dry, and then paint.Paint is cheap enough so you don't lose anything by trying.

These cleaners contain special enzymes that convert organic waste materials such as urine and feces to carbon dioxide and water.

I usually throw everything on the floor out, soak the place with quality enzymes designed for pet urine, and clean everything thoroughly. 

If you want to continue trying to clean them, get a professional carpet cleaner and have them treat it with enzymes or something designed specifically for pet odors.

All under 25 pounds and certain breeds restricted.But our biggest change is in the lease:we let them know that for any animal (note: not pet) the assumption will be 1) the unit is returned to a state where a person allergic to the animal would be able to rent the apartment and 2) a professional cleaning will be conducted at the landlords discretion and the tenants expense, up to and including wall wash, hi powered vacumn for dander, enzyme treatment, killz etc. 3) The expense will be taken out of the security deposit.We haven't had it tested in a dispute yet, but I think it keeps good pet owners careful, rather than prevents bad apples, but it also gives you the ability to do a very thorough job, which should work with most pet damage, horror stories aside.

Or you can use a neutralizing enzyme made specifically for cat odors (search online or ask your vet).