damn, i think mine are 10 years old ... being the heavy smoker i am, i always have a clean one i dont use and one in use ... as soon as some key jams (damn ashes, lol), its time to pop out all keys, dismatle the board ... i wash it in hot soapy water and rinse out well ... after two days of drying i put it back together and it works like before
but damn, a mouse is a different story ... mine tend to die after maybe 6-9 months :/