It's great to see this re-bumped constantly as a reminder that all may not be lost... Like another poster said, if you think it's toast, what have you got to lose? Here are my 2 cents (on special today for only 1cent!):
Once you have all that finished hold it over a sink and pour vinegar "through" the unreachable parts of the circuit board. Do this several times. Afterwards wash it COMPLETELY out with tap water.
Your electronics will thank you if you use DISTILLED water, not tap. You'd be surprised the amount of dissolved salts (magnesium, calcium, etc) is in even "soft" water. Just a little bit of residues inside the electronics can be a problem waiting to happen. Note: DO NOT use spring water or whatever foo-foo H2O you prefer to drink, but true distilled water. Sold at most grocery stores in 1gal jugs for those who don't believe in perma-press and still iron things (not me!). And a home water softener just exchanges sodium ions for the others (unless you use R.O.), so that's no improvement. Be a big spender and drop $1.50 on a jug of distilled at the Piggly-Wiggly.
Piece of advice from a chemist: you can't wash it with distilled water too many times, especially if you just put vinegar into blind nooks and crannies. Rinse it more than you think necessary, then do it a few more times. Be sure to shake out the nooks in between each rinse.
The bag o' rice as desiccant is a great idea, as is putting the camera in a sock or hanky to avoid rice dust. You might also save up those annoying silica gel packs they toss in everything from electronics to prescription bottles these days. Put a few in the sock with the camera.
Don't go nuts with the compressed "air" can - not only can you tear internal bits, but some dust-off products will chill it so quickly you'll just condense more moisture inside instantly (or crack something delicate due to thermal shock.) AMHIK.
I haven't flooded my GoPro yet (knocks on head), but I have about a 75% success rate on recovering from a few other snafus involving electronics and water.
Somewhat relevant advice born of experience: Keeping your cell phone in a front shirt pocket while bending over to flush the head after a dump is a quick way to decide how badly you need a new cell phone. (sounds a little like the joke about snake bites and finding out who your friends are...)
-Don