Whether it's built-up soap scum on the shower walls, ground-in dirt on the floor tile, or dried toothpaste on the vanity top, a Magic Eraser sponge will make short work of it. Just dampen it and rub it on the offending mess. In most cases, the mess will come right off. These sponges are especially useful for removing ground-in dirt from porous floor tile and getting those pesky nonslip strips in the bottom of your tub clean. Magic Eraser sponges are available at grocery stores, hardware stores and wherever cleaning supplies are sold. Unlike regular sponges, they wear out pretty fast, so stock up. While you're out, look for these other very useful household cleaning supplies.