Brush Works Konjac Sponge Black Charcoal is an extremely gentle cleanser for both face and body. Konjac comes from a plant in Asia that grows wild at high altitudes. This Konjac sponge is made from the vegetable fiber of the konnyaku plant. As a result, the Konjac sponge is extremely gentle and 100% biodegradable. The sponge acts as a gentle exfoliator, rubbing off dead skin cells in the most delicate manner.