Excellent info here, but I will disagree that the soap itself does not clean. Yes, it is a surfactant, allowing the water to carry away the dirt better, but most soaps still break down the contaminants (skin oils, etc.), so it really does help clean. Don't believe me? Get real dirty, and try using car wax in the shower instead of soap. Errrr, or maybe not. THAT leaves a bad mental image.