Anyone have any suggestions on what kind of automatic rotary brush to scrub soiled vinyl walls? Walls are now 14 yrs old and the walls in the touch-free bays have slowly gotten away from me. Handbays are fine. My shoulders can't handle the motion anymore . Possibly some form of an automatic rotary scrubber that will do most of the work with acid and still not etch the vinyl. So if anyone has any suggestion on what kind would be greatly appreciated.