You know I have found the best way around a dirty roof. I don't go up there. Roofs are supposed to get dirty and I have learned to live with that. After all, how often do you scrub the roof of your stick house? About once every six months or so I do go up and clean the roof the best I can but I don't waste my time trying to get out all the stains.
Last year at the fall rally we had the Dicor folks in to give us tips on roof maintenance and their comment was, NOW remember these are the folks that warrant our roofs, that the only reason they want you on the roof is to inspect it. Check out all the seams and caulking around the vents and such for cracking and replace as necessary. They also said that the only reason they sell roof cleaning and protectant products is so they know you are using the right cleaning/protectant and not something harmful to the roof such as petroleum distillates, harsh abrasives or citric ingredients. They also said that one of the best cleaners is Dawn dishwashing liquid.
Dicor Roof Maintenance
Truth About EPDM Rubber Roofs
I guess we really will have to persue Dicor for another appearance at the Fall Rally.