Hi Jim,
I have tried dish soap, 303, car wash shampoo and the latest is some cleaner from Klassie that is for rubber & other non-leather surfaces whose name escapes me right now.....bottom line was none were a one shot cleaner. I even tried some of the glass foam sprays...stoner's & spray away. I always end up using a soft plastic bristle scrub brush to get the brown off and then a lot of
303 and a cloth to buff it up.
I have never tried back to black....so I bet that one is the one that works!
