Spot your thumb over it when having your hit, and release it just in advance of your inhale to clear the chamber. Bowls make for excellent collectible glass pieces due to their size and portability. As an added bonus, It can save you the weed you have by now https://cbdoo.blogaritma.com/5734797/details-fiction-and-types-of-weed-vaporizers-for-cannabis-that-beat-bongs-and-joints