I would also try washing the keyboard if I were you; this is the only way to make sure that the problem is with the keyboard and NOT with something else. That said, I also believe that the motherboard (or other boards) is not too easy to get damaged by spilled liquids, since they are shielded by some sort of transparent film after manufacturing, and they cannot short-circuit.
Wash the keyboard, dry it VERY WELL (the fan method should work, although an air-conditioned room would be better) and try it again. Even if it still got issues, but some other key do not work properly, you'll know the problem is with the keyboard.