Castor oil (drug store)-- not Castroil Motor Oil -- is what James Bond (the first) used, but I did it WAY before him -- Model "T" spark coil hooked to a spark plug about a foot behind the muffler of a '54 Chevy, with a pesticide pump-spray nozzle brazed into the tailpipe about 6" in front of that, would throw a **** of a clould of pure white -- DENSE smoke behind!!! Not too many people appreciated it, 'specially if they were trying to find and stop us. They couldn't see to drive!!! It's a wonder I "grew up."