Ya know, I've done a lot of spraying and praying with that old $0 combustion I built, with everything from MAPP to spraypaint. It takes practice, but you can eventually get kinda-sorta consistent results, so long as you're using something like ether/gasoline. I.E, Something designed to burn.
I still wouldn't recommend it, for safety's sake, when inexperienced shooters are involved, but it *can* be safe. Experimenting is fine, just don't be stupid about it.