I use Dicor Rubber Roof cleaner and Dicor Rubber Roof protect, I usually spray cleaner on in a roof section defined by roof bracing, use a sponge mop to agitate cleaner on the surface, then use a pressure washer to rinse roof section off and work from front to rear. I have used a hose, but found the pressure washer with proper spray tip works best.
I usually apply two coats of protectant late in evening usually two evenings when roof has dried and sun is going down in the sky.
Also look at caulking at that time, its a good time to clean caulk with mineral spirits and seal any cracks or anything that may look like a potential problem, I use a self leveling caulk also made by Dicor.
That's my two cents worth, others may have different ideas, but most important thing is have someone on the ground while you are up there, and watch where you step, always being aware of your surroundings, it not the fall that will get you, but the sudden stop.