Magic Eraser is actually the brand name of this type of cleaning sponge made by Proctor and Gamble who produce the well-known

Magic Eraser

Erase set-in dirt and grime quickly and easily with these disposable, soft pads. Designed to remove scuff marks, dirt and tough crayon marks from a wide variety of surfacesranging from floors, walls and doors. The eraser-pad design thoroughly breaks up tough dirt and lifts it away from surfacesand does so with only the help of water. Safe to use, no fumes, gloves or chemicals necessary.