Cat Urine Odor Removal
You can see cat urine with a black-light fluorescent light, then help clean and deodorize it by spraying the area with a mist of vinegar.
When seen in black-light, cat urine that has been sprayed on walls shows up as a yellowish splatter and drips. Simply spray the mist of vinegar on the walls wherever the urine shows and let it dissolve. Also spray around the baseboards and let it drip into the carpet just like the urine likely did.
Don't saturate the carpet though. Repeat a few times as necessary to get the carpet just wet enough to penetrate. You can also use a cloth rag saturated in a bucket of vinegar. Dab it on spots the light reveals on walls, floors and the carpet.
When the vinegar dries, clean walls and floors normally. The odor should be gone.
See: Rentals Stink