Dip the towel in a little water and add some facial cleanser. If there is no facial cleanser, add some soap, gently wipe the dirty place several times, then wipe it clean with a towel, and then wipe it repeatedly with clear water until the soap bubbles are gone. Don't put it in the sun, or it will turn yellow. It's best to let it dry naturally. Go back and try. Want the best answer ~ ~ ~