Not all cranks can be saved. I have forced a stuck pedal to unscrew from a crank and it pulled aluminum stuck to the pedal threads through the aluminum crank ruining the crank threads. After all of that work (and it was a lot of work with a long cheater bar) to throw both parts away. If it was me, unless this is a crank to which I am spiritually connected, after a certain amount of effort, I replace the crank and save my best efforts for more worthy challenges. Good luck.
-Will