Go to your local grocery store and buy a product called DIP-IT, it is used to clean coffee pots. 1st -Add the dip-it to a dry glass bong not the whole box, 2nd-Fill bowl with bowling water and wait a few min. and rince with more boiling water. If bong is really dirty repeat process. When your done clean with dish soap and cool water. Enjoy.. If you try this cheap method i guarantee you will thank me and be amazed by it. It will make an old glass bong like brand new again. I have used this method for 30 years and there is no better way