I have a dog that occasionally has an accident inside the house. Of course, she pretty must exclusively does this on our light carpet. I feel like I'm fighting a constant battle to keep previously cleaned areas from having dark spots re-appear. I've been looking for a carpet cleaner that does a good job of not only getting rid of the stain but also being sure there's no residue left to attract dirt--without having to rent a carpet shampooer or pay professionals. The Hoover Dual Spin Pet Plus Carpet Cleaner does a pretty good job. It quickly removes even set in stains from the carpet. Like most similar carpet cleaners that I've used in the past, it takes awhile of slowly moving the cleaner back and forth over the carpet to suck up all water/cleaner. I only wish this had an option to rinse with clean water at the end to be sure all the carpet cleaner was washed off of the carpet.