shotgunning might be a bit more efficient (there's probably still some thc in the smoke you'd otherwise exhale), but it's nowhere near twice as efficient. The actualy 'blowback' smoke will have much less than half; the reason it works so well is that you also burn more weed while doing it (that's why the joint is in the person's mouth). So, added efficiency yes, double no.

If you really don't like the idea of putting a lit joint backwards in your mouth, you can skip it; just take a big rip, have the other person exhale, then breathe into his/her mouth. This is also referred to as a shotgun, at least around here.
Solistus Reviewed by Solistus on . Save 50% of your weed for free! I just lost my blowback virginity and it was fucking awesome haha! I didn't even know what it was untill tonight! It might be because I've never smoked in a pipe or a bong before but it was awsome! It was like smoking but so cool it just felt like air going down my throat! Then I figured... hey this could save me a fuckload of money... becuase you smoke the same ammount but 2 people get high!... Im so happy right now whoot! Oh by the way If (like me) you didnt know what a blowback is then Rating: 5