I have used cyano for exactly what you describe. "Zap" is probably the best cyano regularly available, but there are others. If you don't use a lot of it, do as Lew suggests and get Zap.
I cyano'd a dowel in a blind hole, needed to get it out, so warmed up the part, the dowel shot across the shed, pinging (gently) off of the wall. The entrapped air under the dowel had expanded, when the cyano degraded the air pushed the dowel out with some force.
So it's probably best to consider "what could possibly go wrong" as well!!
best of luck
cheers
Bill