On my recent camping trip, I sprayed a DEET-based insect repellant and got some on the black vinyl doorposts. The stuff will not come off with any ordinary cleaner, including 303. It looks like lacquer was sprayed on it, and it seems tightly bonded to the vinyl. Attempts to scrape a bit off leave a mess, maybe pitting the vinyl. Any suggestions on how to get this stuff off. Should I resort to the orbital buffer?