Hey you've all seen them. Those air-vent up the glass tornado or cyclone bongs. http://www.grasscity.co.uk/img/products/bush_buzzard_bong.jpg What do you think about them? I've gotten good hits, but I've heard it can be harmful to reintroduce air in the smoke....
Take a look at the bong in the link above. It's made to make the bong rip swirl up the discharge cylinder and the way it does this is by having holes in the discharge cylinder pointed in a certain direction. One can take fat rips with this bong. here's a link to check out: HurricaneBong.com - Hurricane Bong Online Shop | Hurricane Bong | Hurricane Bongs
My bong has holes that shapes the smoke into a stream of milk. I never really knew what they were for, but i've used it for catching ice... Not sure if it's thats what it is?
Why would it be harmful to "reintroduce air into the smoke?" I swear some people don't think about what they're writing when they're writing