Re: Who sells Dessicant/ Silica packs?
Any store which carries a good line of electronics should have lots of little packs, which I'm guessing, typically get tossed. So in a pinch, if you make a contact at Best Buys, or Kragen etc, you can get stacks of the little one's for free. And I imagine that 1/2 dozen or so in an ammo can would do the trick.
In a pinch, cat litter works also. Toss half a cup into an old sock or stocking, tie it shut & you should be GTG. That & it too would be reusable via drying it out in the oven. It's cheap & KISS.
Rice can work as well too. Ever notice how in some resturants there's rice in the bottoms of the salt shakers, especially in humid climates... it's to prevent the salt from clumping.
When I'm out at sea, I always make sure that there's a bit of rice in any jar which has matches inside. Ditto for the survival matches I have in my coat, & packs, + camping gear. It works both for paper ones as well as strike anywhere's.
Rice is also often used to help with drying out electronics which get dunked. It helps to suck the moisture out when you place the soaked item in a bag full of it.
Though depending on what it is, often times I'll rinse the item in isopropyl alcohol first, to flush out as much of the water as possible. As the alcohol dries quick & clean. Particularly when compared to say, salt water.