There are ways of producing more smoke, but they also produce more fouling. If you were gonna throw-away the pistol instead of clean it, and you are after a pyrotechnics display, I could clue you in on how to achieve the results you wish (for a brief period of functionality). But since you didn't say that you needed to do this for a professional movie-making endeavor, I chose NOT to stick my neck out...
Claude said it best...we don't play with guns here!
Dave