Smoke effects

I've been looking into the possibility of a smoke machine for special effects but it would be difficult in outdoor settings - carrying all the extra gear and power supplies . I did some research and found that mixing 3 parts potassium nitrate [ saltpeter ] to 2 parts brown sugar , in a frying pan , creates a 'treacle' that , when set , makes for a very good smoke bomb . The smoke is non-toxic , it burns very quickly and produces a lot of smoke .
I just need to get a metal dish so I don't leave that residue behind during outdoor shoots .