theres an additional way to do this. boiling it makes it soft whilst its hot, but it doesnt restore its pliability. but there have been a lot of people posting in various forums that they have had success restoring the pliability of hard rubber components like carb rubbers by boiling them in hot water with wintergreen oil, (the stinky stuff that sportsmen rub on their legs to keep them warm in the winter) pop the pan on to boil, when its bubbling away, add a layer of oil on top of the water pop in the part to be restored, then put the lid on the pan and boil it for 20 minutes. the oil softens the rubber and it remains pliable even when its cooled down.
