The stuff I picked up is designed to be used specifically with food. Not an issue for me.
Turns out that for me the easiest way is kind of old fashioned -- I tossed them into a small mesh bag, let them do a cycle in the dryer

It's heat, but not too hot, plus air. Worked quite nicely.
Afterwards, the clean, dry, cartos are tossed in a small plastic box with the desiccant pack, for storage until I need them.
(the warehouse that sells them is only 20 minutes from home, so I picked one up after work rather than paying S&H)