Ya wanna scare ISIS? Instead of flamethrowers we need bacon grease throwers.
That would be lard.
Those two choices are not mutually exclusive.
Flamethrowers don't care what flammable liquid fuels them.
It bears serious consideration, whether "international law or agreements" prohibits its use or not.
I'm sure international rules of war prohibit children suicide bombers, execution by burning in cages, or by drowning, or by sawing helpless prisoner's heads off with a dull knife.
Think of the hog farm subsidies!