A chillum, sometimes called a chillum pipe, glass chillum, one hitter, glass one hitter, metal chillum, discreet chillum, or cigarette chillum, is a type of clay (or glass) pipe used for smoking that first originated in India.
How do you clean a one hitter? A one hitter will fill with resin after you have used if for a while, clogging it and making it unsightly. Carefully use a lighter to heat the outside of the bowl to soften the resin and use an unfolded paperclip to scrape your glass one hitter. Do the same with the stem of the pipe making sure to be careful around the mouthpiece so you do not chip your one hitter. You can also boil your one hitter in a soft boil or immerse your glass pipe in isopropyl rubbing alcohol to clean your one hitter. Make sure to keep some strong soap around to wash your hands too.