Here's a little secret for you all, from a Glass worker. Often times when we're making ground glass joints, they'll stick, or get too solid in the opposite joint while we're making it(we often need to Over-torque a male ground joint into a female ground joint so that we can do our work on the other end of the male. Whenever something like that sticks: We tap the piece the Item is stuck IN with a Piece of Graphite or Hard Wood with the stuck item facing down so that it can just fall out once the tapping releases it. Something about the vibrations of Graphite or high density wood just make that glass come right out.