I have a piece that had a pinhole leak in it from GBD.
It was small enough that I couldn't see it with the naked eye, and it didn't seem to affect the hit, but if I left the piece with water in it, and came back 20+ mins later, it would have dumped all its water out...
I went to my local hardware store and got some glass epoxy. It sealed up the hole nicely and hasn't given me any issues since.
The epoxy was for repairing drinking glasses etc. so I'm fairly sure it is food safe...
It has minimal contact with the water/vapor, so I'm happy with the safety of it for this application.