CRYSTAL FOAM is a unique foaming shampoo designed for use on carpets and upholstery using either: a rotary scrub, dry foam, or bonnet buff method. CRYSTAL FOAM develops a rich lather, which lifts and encapsulates soils and prevents re-depositing. The residual foam dries to a brittle crystal, which vacuums out easily. Soft on velours. Pleasantly scented. Easy to use by hand.