Try boiling water, not just hot.
You could also try the door technique - Simply open the door and put the grip in between the and the door frame on the side so the door closes towards you (so you have to pull the door closed) then grab pole and pull while twisting. It always works for me., but to be on the safe side look and see if there are any screws (there's probably a screw on top of the grip to hold the strap, it shouldn't matter, but you can take it out anyways) if you see any take them out and give it a try.