First of all, you should brush off the dirt from the Sunbrella fabric before it gets absorbed. In case of new spills, soak up the liquid using a soft, dry cloth, wash the area with a mild soap and water solution, rinse, and air dry. For more difficult-to-remove stains, create a mixture containing 1/4 cup of mild soap per gallon of warm water, lightly scrub the stain with a cloth or soft brush, rinse until it is clear, and allow the pillow to air dry.