Impregnated surface with full of chemical clay and iron powder. Water stain and oil content of the wax are removed at the same time when washing. The oil content of the wax is also remove, the coating of the next process can be done smoothly.
Since the surface of the sponge is impregnated with chemical clay, iron powder (impurities) and scale can be easily removed at the same time (soak the sponge with a scale remover). Since oil such as wax is also removed, the next process work is smooth and high quality is finished.