The main problem in choosing a cat urine remover is that most do not remove the salt crystals found in uric acid (a component of urine) that produces that nasty cat urine smell.
These crystals are non-soluble and washing with ordinary urine cleaners or inferior products will not remove them because they become bonded to the affected surface.
While it may appear that the urine stain is gone after cleaning once the soiled area gets wet again the cat urine smell will return because these crystals become part of your floor or carpet.
This is true even if it has been several years since the cleaning! Also, remember that a cat will be able to smell this even if you can’t and will often urinate in the spot over and over.
A cat urine black light detector is an indispensable piece of equipment in that it causes urine spots to glow in the dark. Without one you really are just guessing where to clean and can easily miss spots.