With a New Keyboard, Water Would Do More Damage
Most new keyboards (the last, maybe, 12 to 15 years or so?) work using two plastic membranes with painted traces to carry the signal to make the buttons work. Water will corrode these traces and make the keyboard inoperable. Older keyboards could be put under running water, shaken out well, and let dry, but with any semi-modern keyboard you'd expect water to do more harm than good, unless you disassemble the keyboard and run water over only the shell instead.
Of course, with a keyboard like that, the original drink would probably finish it off anyway. You might be able to disassemble it and clean the membranes with alcohol and the keyboard with water. You can also repaint corroded parts of the traces with conductive paint to resurrect a keyboard that has been damaged this way, but usually it's not worth it. (Though I type this from an older Microsoft Natural keyboard that I did just that to, but if I had gotten a new keyboard, it would probably have been a regular one instead of an ergonomic one.)
