wot do u mean by killswitch? if ur talking about a killswitch from a motorbike then id recommend against it as when u strum u have up and down motions but attach a killswitch and you only got 1 motion,unless you attached 2 killswitches and used one finger to operate each...which would be pretty damn cool,cos u could use the littlest movement possible while playing guitar hero preserving your energy,meaning u can play gh3 for longer