Picked one of these up on a whim in Tesco, thought I might try it on some stubborn small black spots on the m/h roof (although it says not to use on car bodies ) and it worked a treat. Also cleaned up the greying surface of the mastic seal around the hab door frame and cab/roof joint. It doesn‘t appear to be abrasive but does have a detergent incorporated in it that‘s activated when you wet it.