Steps. 1  1. Get liquid dish washing detergent and white vinegar. Mix one tablespoon of each with 2 cups of warm water. 2  2. Get a clean (white) cloth. Sponge the stain with your detergent/vinegar solution, blotting frequently with a dry cloth until the stain fades. 3  3. Sponge the stain with cold water. Again blot until all liquid is absorbed.