I found that using the Thetford Black Streak Remover which takes it off in a heartbeat not only cleans it, but it also prevents mold from from coming back so quickly even though you rinse it off.
Don't know why but I've tried everything when I was parked down South and cleaning with this really did stop it from coming back. It must leave some sort of surfactant behind that prevents it.
We must be willing to get rid of the life we've planned,
so as to have the life that is waiting for us.