You're Right! Lava Soap may not necessarily be the most glamorous bar soap ever made. Its gray color may fit in better with the color scheme of a prison than with kitchens and bathrooms in the typical American home--- but when it comes to washing hands completely clean from dirt and gunk, it was simply the best in the business. The reason why Lava could do this could be linked to the product's name--- and the volcano on the Lava box. Each regulation gray Lava soap bar contained powdery pumice--- the same stuff that comes out when a volcano belches. The pumice combined with a gentle soap cleaned hands thoroughly and fast--- although the timing it took to do this varied.