Are there any quick, reliable methods for setting someone's clothes on fire? Please see details.

Preferably at distances slightly greater than the reach of one’s arm.
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No, I’m not planning on trying it out. :D

I’m writing a short, somewhat comical story (personal amusement, it’ll never see the murky light of the interwebs) where, at one point, our hero thwarts his own kidnapping by setting his kidnappers’ clothes on fire and running off while they run around in a panic.
Earlier versions involved a flare gun, but I kind of get the feeling that point-blank flaregunning would be more lethal than what I have in mind. I want the “Zomg-I’m-burning-ow-crap” that’s in the second panel of this strip, only with more MacGuyver and less plasma cannon.