You'll never win, and you'll never convince these people that their house smells like cat piss. Yes even if they clean it two times per day. No matter how often they clean the litter boxes - everyone who isn't a cat owner can smell it.
I don't know what animals you've had, but my cat cleans herself (including paws) pretty much right after leaving the litter box, and continues to clean herself all throughout the day.
Wait until I'll tell you what human children do with their hands before proceeding to put them all over the place.
Sorry what was that I didn't hear you over the sound of THE PARASITE LIVING IN YOUR BRAIN THAT YOU GOT FROM YOUR CAT WALKING IN SHIT AND THEN WALKING ALL OVER YOUR FOOD.