Silicone bongs are made from BPA-free rubber and are damn near indestructible. You can even clean the silicone in your dishwasher. The biggest advantage of a silicone bong is for travel due to how durable they other. But for performance, smoothness, and taste a glass water bong will out perform a silicone one 10 out of 10 times. Glass bongs are made from high-quality borosilicate glass and are individually hand-blown. With proper cleaning, a glass bong will last for many years while silicone bongs should be replaced after 1 year.