Fill a spray bottle with warm water and add mild dishwashing detergent to create a soapy solution. In general, 1 to 2 tbsp. of detergent per 16 ounces is enough.
Spray the entire outdoor chair pad with the solution. The spray should cover both sides thoroughly, as well as the edges of the pad.
Scrub the cushions with a sponge to work off dirt and debris.
Rinse the outdoor cushion with warm water to remove all traces of soap.
Use a towel or dry sponge to wipe off excess water. Allow the pad to dry for 24 hours in a well-ventilated area.