Remove stains from vanities made of marble or other natural stone with white toothpaste. Cover the discolored areas in paste, rub lightly with a soft cloth, then rinse and repeat, if necessary. If toothpaste will not remove the stain, dip a lemon wedge in salt and rub it vigorously over the stain, and then rinse well. Using a lemon wedge should be a last resort; prolonged exposure to citric acid can erode marble surfaces.
Clean wood vanities by washing them with a solution made from 2 quarts hot water, 1 tablespoon turpentine and 1 teaspoon liquid soap. Apply the solution with a soft cloth, and then rinse and pat dry. Sprinkle baking soda over any sticky spots, scrub gently, and then wipe the surface clean with a damp cloth.
Cover the stains on plastic vanities with a thick layer of liquid automatic dishwasher detergent. Scrub the surface briskly with an old toothbrush, and then rinse with lukewarm water and repeat, if necessary. Do not allow the detergent to dry out. Automatic dishwasher detergents often contain bleaching agents that can cause plastics to lighten.
Spray glass vanities with white vinegar, wait 2 to 3 minutes, then wipe with a paper towel. The acetic acid in vinegar is capable of dissolving everything from hard water deposits to blood stains. Stubborn spots can usually be eliminated by dousing them in a stain-busting mixture made from ¼ cup clear ammonia, 2 tablespoons white vinegar, 1 tablespoon baking soda and 1 quart of warm water.