wire your output to ground.... that's the basic idea of a killswitch.
Don't just cut the connection.
Note, there will be some switching noise when using the kill switch on clean - but people seldom do kill switch clean, they would use a Tremolo! - but the noise is neligible when on dirt.
Uh... what would u be using?
I use a momentary / non-latching button that when depressed, grounds the output. I find it easier to use than the 3-way and it allows for more rhythmic kill-switch-ing, since its a button. Just need to get used to it because people are usually accustomed to pressing a button and hearing sounds, not the other way round.