I use a lightweight leaf blower, standing on the main roof. It will take off leaves, twigs and even rain water. I plug it in to the outside outlet, tie a lightweight rope to it (about 15’ long), climb the ladder with the rope looped through a belt-loop then, when solidly on the roof, pull up the blower. I use a cord that is long enough that I can move and catch all three slides, on both sides of the trailer, as well as the entire roof area. When done, I let the blower back down, using the rope, then carefully climb back down.
It is a little noisy but, at 10-11:00 in the morning, who really cares? Plus, it works like a champ.