There is a lot of ways people clean glass pipes. We recommend the one below. It is important not to boil you glass, as it can weaken the glass. Also stay away from harsh chemicals.
Directions on Cleaning A Glass Pipe (You will need a Ziploc bag, salt and rubbing alcohol):
Do this in a place that can be easily cleaned, just in case a spill. You don't want that liquid on you favorite seat in the house.
Disclaimer: This if for informational purpose only, and we do not guarantee results...