when i was tweakin i used those cause tweakin makes u sketchy as shit. noticed that i still smell a stoney flovor(nothing to worry bout) an i got all paranoid an built a serious odor extinguisher. took a 2 liter an like a bong had water an a tube goin down to bubble all the way to the top almost. i soaked the water with potpurri an had a couple dryer sheets on the top. remember i only built this cause i was tweakin an paraniod. i dun even need to worry bout people smellin my weed cause i only live wit a homie. thats the funny part.