We kick off Flamethrower Week!
Flamethrowers are fantastic for cleansing and burning hordes of the undead, giant mutant ants, vampires, witches... Well, just about anything. Very little stands up to the purifying power of open flame. But they remain special purpose appliances, and not part of your everyday kit.
Still, when the job calls for a flamethrower, very little else will suffice.
One problem is that you can't use flamethrowers inside enclosed structures because it's a major danger to you own self. The other problem is that flames don't act instantaneously. Douse a zombie in napalm and for the longest few seconds of your life you have the only thing worse than a zombie -- you have a zombie on fire! It'll keep shambling right toward you ablaze; at least until the heat starts making the tendons contract and the zombie collapses into a ball of charcoal.