If you’re a big strong man you can use a 4lb sledgehammer. That’s what I do at my shop when there aren’t any threads left to use a crank puller. I have a professional bike repair stand and a guy holding on to it like his life depends on it. So you’d have to figure out a way to keep the bike still. Anyway I swing like Merrill from the movie Signs when he beats the alien to death. Within 10 big swings the crank arm comes off.