There's a rivalry in Hucksterville, as Billy Mays has called out Shamwow's pitchman Vince Offer to claim that the Zorbeez chamois was the original and bitch shouldn't front, etc. According to PopMech there was even some rapping involved, I'm sure to the embarrassment of everyone but those who make a living by being shameless.
PopMech tested out both. Turns out Shamwow is a lot better.
But here's the thing: they're both just synthetic chamois. And they're nothing new. You can pop down to your local auto parts store and pick up the classic "The Absorber" for about ten bucks. Same stuff (or better), comes in a handy protective case, lasts for years, and won't entice anyone to rap.
Above, a video showing how similar the pitches are for both the Shamwow and the Zorbeez. The Shamwow may be a better product, but they definitely ripped off Billy Mays. But who cares about Billy Mays?