Well, it might be a way to actually kill a spirit wielder. Emphasis on "might."
I don't really have much of an idea how pipe bombs are made, but still, it's not as crazy as some of the things that I find in video games.
Take this in mind: In Fallout 3 & New Vegas, there's a weapon called "Fat Man." It's a pneumatic launcher that literally shoots out miniature nukes at whatever you're pointing it at, & since the blast radius of those are just ridiculous, plus the fact that the projectile has a parabolic arc to it, seeing that the weapon is pneumatic, it's way too easy to kill yourself using it unless you're far away from ground zero.