I've always read to keep the pack in the fridge to reuse, I just got a covered rectangular plastic storage container from my kitchen and keep it there. Here's an article that says you can reuse 25-30 times.\
Btw, I started 5 days ago and could feel right away that "something" was happening, I don't know how to describe it but it felt like there was some "activity" in my liver area and for me it's been a very relaxing experience. I had done my first in the afternoon and felt like I needed to do it again at bedtime so I did. The very next day I noticed an improvement in my bm's and the color had changed, for a while it had been lighter, which I'm sure signaled to less bile output, now the color is darker/greenish again (I've also been eating lecithin granules) so that's very encouraging.
Oh, and maybe it's a coincidence but I've been sleeping better since day 1, most nights I even fall asleep a while after putting the pack on and wake up at least an hour later at which time I turn off the heating pad and either remove the pack or cover it better to leave it on until I wake up again.