Always wear eye and skin protection to prevent liquid or other materials from entering your body.
After a soaking rain or anytime the cores of the cushions get wet it is best to stand the cushion on end to allow them to drain more quickly. This will prevent mold and mildew growth between the frame and the cushion.
Spot wash the fabric to clean spills by using a sponge or a soft bristle brush with a warm soapy solution of mild detergent (Joy® or Ivory® liquid). Brush or sponge the soiled area and rinse thoroughly with fresh water. Allow to air dry. Repeat if necessary.
If and ONLY IF your cushion is made from 100% solution dyed acrylic such a Sunbrella®, you may use one part bleach mixed with one part water and a mild dish soap to clean your cushions. Be sure to rinse the cushion thoroughly to remove all of the bleach solution.