http://www.amazon.com/Gram-Silica-Ge.../dp/B006LMDBS4

$25 bucks for 5 and you can reuse them if you have a 200 degree oven.

If you buy the stuff up here (arid environment) or keep it in the open up here for a bit, recharge a bunch of these things and seal em up, should be good to go. If you keep the metal surfaces properly lubed before and after touching (I grew up in wisconsin, fingerprints turn into rusty fingerprints in days.) I think you would be good. I read somewhere that the desiccant that you get at walmart and stuff in the bucket is actually an acid, you may want to steer away from that stuff.