I don't know how this stuff works, but Bissell Oxy Magic is the bomb! I have used a variety of other carpet cleaners with varying success. At one point a carpet cleaning company gave us a bottle of professional cleaner, and I was hooked. The trouble was, I could only get it through their company. Then when I saw Bissell Oxy Magic at the store, it seemed to be a similar product, and it turns out that it was--at a fraction of the price! With two small children and two cats in my home, our carpets have seen their share of stains. Anything from grape juice to play dough to leaky poopy diaper messes--yuck--have been cleaned by Bissell Oxy Magic. You spray it on the spot, then walk away from it for five minutes. When you come back, you dab up the excess liquid. Spot's gone! This probably is not recommended at all by the Bissell company, but I think that it's a testament to this product's stain-lifting ability: I had a pair of jeans with a large blood stain on them that I had already run through the wash on warm water. Not good. Then I forgot about them and let them set another couple of days. I debated throwing them out, but then decided to try this carpet cleaner on them. I mean, it gets grape juice out! So I sprayed them and left the room. When I came back, the stain was gone. Just gone. Weird, but it works!