I've found my method to be fairly effective, but it's very high tech, and not a lot of people will have access to such a device. Plus it's loud.
Having said all of that, try doing what I do:
1) pick up the mouse between the thumb and the forefinger
2) bring the mouse near your face
3) aim your mouth at the ball
4) give a sharp burst of air, and simultaneously think very hard about all the little dirt particles flying out.
🙂
Truth be told this works most of the time for me. Canned air works too, but that seems like overkill for me.