I can't speak for all of them but hoppes #9 has not harmed the one I got from WamoCamo. I even wiped a grease stain off with acatone and no paint came off. I was going to email sixT first to see what solvents might hurt the finish, but just went ahead and hit the spot. I was expecting to see some paint on the rag. Nothing came off but the spot I was removing :!: .