I have cats and a very light colored carpet only 8 months old. The little dears are terrific about using their litter boxes so there's no problem there but they will run 10 miles through fire to be able to throw up on the carpet. The spot that brought me to you happened while I was at work so it really had time to settle in. I tried everything I had on hand but I could still see the spot. Then I tried Oxi-clean. Ohmygod...don't do it. The spot got bigger and bigger and turned brown. I found you while surfing so I ordered the 2-pack. It, of course, got lost in the mail so Greg sent me out a new batch. I'm in love with the stain remover. It does a beautiful job. I keep some in a spray bottle so I'm always ready for the next hairball. Thanks, Greg!