How often should you use cleaner/conditioner on your roof?

My Dutchmen Lite has a roof you cannot walk on so the only way to clean it is from a ladder against the side. Good luck on that, you will end up taking a bath in whatever you are cleaning the roof with. You can of course erect scaffeling or try hopping about and moving 3'x 3' peices of plywood to stand on. You can, I am to darn old.

At best my roof will get a once a year bath with a garden hose and an inspection of the seals from the a ladder.

Dirt does not leak, seals, cracks and worn spots leak.