I've heard of that "Jar of sharps" one before. It invokes a screeching, howling spirit like a scalded banshee, only worse, that brings "madness and a sundering of reason" to any who hear it's dour wailing. It carries desolation even in it's cacophonous nasty echoes, and is best avoided altogether. Not pleasant. Even if it's banishing spell is fairly straightforward. Best leave that one at the door, innit?