[Cougar1957]

I've tried all these methods, and none have worked for me. Keep in mind that I was dealing with very stubborn stains from a black walnut tree. The one thing that finally worked for me was the green bottle of Clorox Clean-Up Cleaner+Bleach. I highly recommend this. Just wet the surface, spray on, and lightly scrub with a soft to medium bristle brush, then hose off. Make sure to wear clothing that you don't care about, and also wear eye protection. Good luck!