i think i just invented the need for a glass joint smoker for a bong because there arnt any online. not even silicone plug versions yet.
update
https://www.thingiverse.com/thing:5677679 found this one but i was thinking more of a cap design with a hole in it. or even retrofit existing bowl with wooden inserts.
https://www.thingiverse.com/thing:5677679 found this one but i was thinking more of a cap design.