Yes, the boiling will work with antler. That said, it needs to boil a long time and you have to be able to push the tang all the way in with one push. If you stop it will hold tight. I've used this method making a couple of patch knives but have switched to drilling a hole and using epoxy. I've also drilled slightly undersize and boiled the antler then pushed the antler onto the tang as the blade was held in a vise. By the way, boiling antler and horn usually have a smell that most modern folks find less than pleasant.

YMOS,
Tony