I've heard recommendations of your product on the web and read reviews on your website but have not seen anything specific to my issue. I had a Trex Escapes deck installed about 7 years ago and overall it has been fine but over the past 3 years I've had a large silver maple tree grow over it and it seems to be dropping dirt combined with sap on our roof, gutters and trex deck. It appears simply as ground in dirt that I can't remove so I can only assume the tree sap is part of it. There is no obvious sap to be seen. I've had a power washer (electric, 1800) that has been able to clean it off (water only) over the years but it's gotten to be too much for it now to remove via pressure washing. I've tried to scrub w/vinegar but doesn't seem to do much. The first bag of Corte Clean did wonders with my deck so I just ordered more. It was amazing how it would break down the black mold so effectively!