I know I might get some people disagreeing with this but... I've heated gear in water on the stove, poured hot water over it constantly, wrapped it up in a wheat bag, rubbed it between my hands and a whole bunch of things. I have to say though I've found the microwave for a short period the most effective and I've never noticed any loss of potency. Otherwise I just heat a wheat bag up and sit it in that until it cools and have never had a problem that way either. Put it this way, in it's current state it's unusuable so your not really in a position to lose anything no matter what