The rice sack idea sounds promising. I'm pretty sure you'll be fine, after all it's a keyboard - there aren't too many places where high currents could run, so you probably won't damage it by plugging in if it isn't perfectly dry; the worst thing that can happen with any probability is you might lose functionality on some keys, but I guess there are enough offers for replacement switches.
However, if it was my board, meaning that the owner didn't care about losing warranty at all and was a lot less worried about damaging his expensive stuff right now than having to order and wait for comparatively cheap new parts later, I'd try the following:
Remove all keycaps, open it up and carefully but thoroughly wipe it dry, using paper towels and q-tips. If it looked like water might have entered the mechanics, I'd flush it all in pure alcohol (don't use any diluted stuff, it may leave a residue when dried) or, even better, isopropanol. The alcohol will absorb the water and obviously it will dry off a lot better; also it doesn't corrode the metal parts. However, it might damage some rubbery parts, so be warned - I'd still risk it unless some gurus here warned me not to because they've tried it on the exact type of switch and faced problems.
Then let the disassembled parts sleep in a warm and dry place for a night or two - the inside of a rice sack on top of a heater sounds ideal for that purpose, but if you flushed it with alcohol, any dry place will probably do. Check for any remaining wet spots in places you can't get to (if needs be, let it dry some more) and reassemble.
Chris
