The Mudsponge is a great all-purpose pop-up sponge made of an open cell material that is very absorbent. It's shaped like a potters rib to fit comfortably in the palm of your hand. Dyed with a natural pigment, the color will fade with use.
Natural sponges have been used for years. However, the quality of natural sponges can be unpredictable and there is the issue of environmental pressure on the little guys. These sponges are made of an environmentally friendly material that is incredibly durable and compressed for economy of space and for the fun of watching them expand when introduced to water.