In order to restore the inner lining of your faux leather jacket's sleeves so it's sparkling white again, mix 3 cups (709.77 mL) of warm water with 1 tablespoon (14.77 mL) of mild detergent in a bowl. Turn your jacket inside out. Dip a clean cloth in the bowl and wring out any excess water. Wipe down the inner lining of the sleeves, paying special attention to the stains. Allow your jacke to air dry overnight, then hang your jacket.