The Knockout is the unofficial "Swiss Army Knife" of bongs. Not only can you do Knockouts, but you can turn any bottle into a water bong.
1. Grab an empty bottle.
2. Fill it half way with water.
2. Take off your one-way Duckbill valve.
3. Pack your herb in the one-hitter.
4. Pop the Knockout on a bottle.
5. Toke away.