Braxton-Bragg offers the Dr. Fred's Stain Sponge for stone and concrete. Created by stone expert Dr. Fred Hueston, the Stain Sponge is an easy-to-use poultice stain remover. The bag is soaked in water and placed on the dampened stain, then covered with a piece of plastic wrap. A few holes are punched in the wrap to allow for slow drying of the bag. As the bag dries, the stain is drawn into the poultice inside the bag. After 12 to 24 hours, the bag should be dry, and is removed. There is no poultice powder to scrape off and scrub down.