How much water??? I hope its not too bad, saturated or flooded and glad its not an electronic machine.
Aside from the obvious, wipe dry and lube or worse, drain it out...
Search above for cleaning KMs and you will find sites that show how to break them down for through cleaning. Also other tips about using denatured alcohol and what type of KM oil to apply after its dry, (I like lorilynn's KM oil)
If you need to use a blow dryer, inside the card reader for example, use it on LOW, don't hold it one spot too long (others have superheated their KMs and melted plastic)
Sorry to hear this, and hope you'll be able to dry it out ok.