I had spilled a glass of water on my Xbox 360 wireless controller. At the advice of some tech friends of mine, I put the controller in a absorb bag with instant rice to absorb the moisture out (of course after immediately removing the batteries first). The moisture was taken out no problem, but some rice crumbs got stuck in the right analog stick.
After ordering and quickly receiving the T8 screwdriver, the repair was as quick as disassembly, blowing rice out with air and then reassembly.
Use something besides instant rice to absorb moisture from the confines of a controller.