Marshalltown sponges come in three different styles. The turtle back sponge is a great general-purpose cellulose sponge. The shape conforms to your hand. The Marshalltown Tile grout sponges are used to wipe off excess grout from joints. It has round corners to prevent digging out or marring joints. It comes in either large or x-large size. The tile grout scrubbing sponges are for scrubbing and removing grout haze. It has two sides. The yellow grout sponge wipes off excess grout from joints while the white scrubber removes grout haze and stubborn mortar colors.