This is new to me. I have been asked to restore the paint on a Harley. It has, what Harley calls Denim Black paint. This is a black base with a satin (flat) clear coat. Using any polishes will destroy the finish. I washed the bike using Meguiar's Deep Crystal car wash. It removed most of the soot. What was left , looks like water ( full of chemicals) runs on the surface. Any suggestions would be appreciated.
Try a paintwork cleanser. They are non abrasive cleaners. Swisswax makes a cleaner specific to satin finishes called Opaque. Its not cheap, but I can get it for you if you need it.