If "effective" includes only "not killing civilians", opening a hot dog stand nearby would work as well. However, if it also includes "stop 400 Taliban fighters from shooting at us", the situation become a bit more complex. Smoke would just remove visibility. But Taliban don't need much visibility - they already know where the forces are, they were fighting for the whole day in the same setting, and they probably know the village inside out anyway. And they also don't care if they hit a civilian by mistake, so they can just keep shooting in general direction. And if you use some real active chemistry, the civilians - especially children - would be the ones hit the worst.