If the Strain were "Cat Piss" .... the actual cat piss might smell better.
Maybe Hygrozyme, or something with enzymes will help break it down. Its perfectly good Nitrogen ... its the smell more than anything that is a problem. Well that and being owned by an evil cat.
Maybe kitty sees yellowing leaves in a different light spectrum, a couple days earlier than you and was trying to help..
Spraying hot sauce on the floor at the entrance, and maybe near the pots, on the side etc. should keep them away. Tabasco or a 10+ like Satans blood, Daves insanity or Inferno cut with vinegar would be better...Hot pepper wax is another option. OR sprinkle some hot chili powder on the floor. First.. they wont agree with the smell... and they wont much like getting hot pepper on thier paws.