Laundry stain removers like Vanish do work differently that ordinary laundry detergents. They contain an oxidant called sodium percarbonate. This compound forms peroxides in the washing machine water which removes the laundry stains by bleaching. Some laundry detergents have sodium percarbonate as an ingredient. Detergents remove dirt from fabrics by forming bubbles called micelles around fat particles. This breaks apart the dirt from the fabric and puts it into solution so the dirt goes out with the rinse water. Other agents called builders raise the pH of the wash water to help assist in the detergent action.