Here is a link that may be of help:
http://nonverbla.de/blog/2006/11/12/how-to-clean-your-macbook-pro-keyboard/
You probably don't want to actually drop water onto the subsystem--you don't want to risk water getting deeper into the machine and carrying coffee with it maybe down to the logic board. Coffee is corrosive. It would be safer to use something like a Q-tip dampened with distilled or deionized water and clean up any residue. I would avoid using ethanol--it will attack some finishes. Isopropanol is more benign, but since water will dissolve coffee, I don't think alcohol would even be necessary. I would also just let everything air dry and avoid using any heat on it.
The alcohol might serve as a desiccant to help dry any traces of water, but if you should not be using that much water.
You want everything to be bone dry before starting up.
The keys may well not be working due to sticky residue which has dried below them. Removing this residue completely may well get them working again.
In my opinion, it is well worth attempting this sort of a repair on a keyboard. If something is busted, you don't have much to lose by trying to fix it. If you can't, then you always have the option of replacing the keyboard.
Good luck!