How to Remove Spots from Kitchen Countertops

Fred Hueston mixes flour and hydrogen peroxide to create a poultice that's about the consistency of creamy peanut butter. Peroxide works best for food stains, but in the case of cooking-oil stains, Hueston uses dishwashing liquid, which breaks up the oil. For biological stains — mold, mildew, fungus — he uses household bleach. (The chlorine doesn't bleach the stone, only the stain.) Rust disappears with sodium hydrosulfate, available in over-the-counter rust removers. "I've seen stains go from light yellow to deep purple with the wrong chemical," says Hueston. He always tests the poultice on an inconspicuous spot on the countertop before applying it to the stain.