I came from the circuit board industry and the circuit card that is in your key board will take quite a bit of abuse....the board has either a carbon, silver or gold pad right over the keys. When you press the key it touches that area and that sends the electronic command..There is really nothing on top of the board that water or liquid will cause much damage unless it gets under the board..even then you can let it dry out and it will come back to life....They wash circuit boards fully loaded with component with water once they are done..at the manufacturing sites....The one thing that will cause problems with your key board is dust and bits of food

so I would recommend that you turn that board over every so often and shake it out or use your air compressor to blow it out
OK there is a circuit board lesson for the day