Flush with alcohol, or if you are desperate, flush with soapy distilled water, then distilled water (a lot of it). Your goal is to completely dissolve and remove all sugars and oils from the coffee/milk. From there, you will need to let it dry completely (probably in sunlight or with dessicant) for 3-4 days straight.
Or get another keyboard, and do this anyways.
I brought my Razer Blackwidow back to life using the water method, after I spilled a cup of orange juice on it.