After using aluminum foil, it's best to clean it while it's still slightly warm to remove any residue. Wipe it with a damp cloth or sponge, using a mild dish soap if necessary. For stubborn stains, you can soak the foil in warm soapy water for a few minutes before scrubbing. Rinse thoroughly with water and dry it completely before storing. If the foil is heavily soiled or damaged, it's better to discard it and use a new piece to maintain hygiene and prevent potential health risks.