I replace quite a few handles for vintage socket chisels. I first shape the profile to fit the socket and then leave the chisels on the sheet metal top of my oil burner for a few days. This removes just about all of the moisture in the wood so that when the handle is set, it stays set.
Years ago I shaped a handle and then set it into the chisel. I was working outside and it was a sunny day. After a while I picked up the chisel by the handle and the metal chisel head fell off. That's when I started drying the wood first.