Would be a great conquest, indeed! But I wouldn't be too optimistic before having seen it. The drive is for sure easily replacable. But the mobo… if it's actually fried, i. e. heavily short-circuited, I don't think that a simple washing will be be enough. You may be better starting o look for a cheap dead MacBook whoose mobo is ok, in order to switch them!
Anyway good luck, and let's hope you're right!