A poultice is a liquid cleaner of chemical mixed with a white absorbent material to form a paste about the consistency of peanut butter. Spread it over the stained area to a thickness of about 1/4" with a wood or plastic spatula, cover with plastic, and let sit for 24-48 hours. You may have to repeat this process to thoroughly remove a stain.

Oil-based Stains: Poultice with baking soda and water OR mineral spirits

Organic Stains: Poultice with baking soda and hydrogen peroxide solution OR acetone