Anti-Icky Poo is an enzyme cleaner our vet recommended to us for some litter box problems we had with a cat. He said it's what clean-up companies use to take care of "organic residue" at crime scenes. I'll let you figure out what that is by yourself! We ordered it online and it comes with a very large/scary syringe to inject it into subfloors, walls, and materials beyond just the surface of carpet & padding. It's astounding how big those stains are in reality if you use a black light to see them glow. Yes to carpet protection film! I wonder if you can wrap a matress & chair pads with it.....
Great recommendation lyndaferg! You might also consider using the carpet protector plastic in prone areas, the type they use in showcase houses in high traffic areas. It's available in rolls in lowes, Home Depot or other local flooring centers.
I'm not sure about a carpet protection.. but with my father, when he would have *Accidents* in his room, I would use Nature's Miracle to clean up the rugs & his bed. It breaks the enzymes down to eliminate the stains & odor, but doesn't harm the fabric. Not to sound disrespectful, but it is sold at Petco & Petmart.