yes, mickeyray, that or kalk them, or drop them in a bucket of pool chlorine, or even put them in a nuclear reactor. but, if you don't kill each and every single one of them, they will come back.
generally, epoxy or superglue over them kills them off. nothing eats them (that i know of) and they WILL kill fish. oh, and if you touch them, you'll be in some good pain... so use gloves