I live in Oklahoma where we have lots of red dirt. A kind of wasp we call mud dobbers or dirt dobbers (sp?) likes to build nests of red mud in our mainsail while it's covered with the main cover, and the boat is not in use. When you break up the nest (hopefully already vacated by the wasp)there remains a red stain on the white sail which is probably red clay and wasp spit. No soap scrubbing or bleaching I've tried can remove it. Does anyone have a way to remove the stain?