Occasionally, we will leave our boat uncovered on the boat lift... and each time we do, we regret it. We are on a creek in Maryland that leads to the Patuxent River and our shoreline is heavily treed. So when the boat is uncovered overnight or for any several hour period, the upholstery will be soiled with, what I can only characterize as, tree droppings of a light brown color in the 1/4 - 1/2 inch diameter size... once these spots are dried by the sun, they take significant elbow grease to remove. Is there a product out there, that can remove such stains without the need for serious scrubbing and... that will not harm the upholstery??