If the threads are stripped, I would think it is no longer "an otherwise decent crankarm".
I'd "ride it off" as that is least likely to damage the bottom bracket or frame. All of the pry and beat techniques have a strong likelihood of doing collateral damage.
I agree, a stripped crank is no good. If you can get it off without damaging anything, can you do it twice? But seriously, the "ride it off" method is dangerous. I tried going up a short, but very steep hill several times and gave up. I turned around (with my feet off the pedals) and the crank fell off with no warning. Had I been on the pedals I doubt the vasectomy debate would still be relevant (it was a large bike).