Everyone's giving solid advice to a frustrating situation.

I would torque it both ways, sometimes it breaks the seal going in the wrong direction.

Sounds to me as if there's something sealing an already too tight fit but I've worked on pipes where the smoker glued the stem in.

I'm in @EmperorZurg's camp, it has to come apart to have value. @GWBowman advised using a pipe retort and that could help if you haven't tried that.

Good luck.