I made this simple, yet awesome Fuze bottle bong this afternoon. The plastic on these bottles is pretty thick, and it stays rigid when your pulling, unlike crappy water bottles.. I wrapped the downstem with a couple of layers of Ductape to make an airtight fit. Thought it looked sexy and Im ripped so I felt like sharing:
It's the small metal bowl on top of the stem in the pic. From a Black Leaf Bong I had back in the day