Unibody Mac pro F6 key not function. I saw some brown areas under the key, when I remove it. How to clean it?

I lost my F6 key of my unibody mac pro after coffee spillage. :/
There was no sugar in the coffee. However there are some remnant of coffee which results the F6 key not functioning condition. I saw some brown colored areas under the key, when I remove it.

How should i clean it. Is using a hypo and some alcohol applicable?

Tagged as:  alcohol · colored areas · f6 key · remnant · sugar in the coffee · unibody