hmmmm...let's revisit this. got the Wolfman bags clean, now my Ortlieb duffles were looking terrible in comparison, time to try to clean those up. the Ortliebs have been all over the place, the large in particular, including maybe 15,000 miles with a spare tire strapped across the top. the vinyl cleaner took most of the grime off, but would hardly touch those dark black scuffs from the tire. had some hand cleaner and tried that stuff on the black, bingo, cleaned right up. thanks, turned out to be a good tip, saved a bunch of time.