compressed air
NOOOOOOOOOOOOOOOOOO!!!!!!!!!!!!!!!111111111111111eleven!!!!!
never, ever, for any reason, ever at all under any circumstances consider the mearest possibility of squirting compressed air at your sensor!
did I mention dont do it?
some propelant is fairly likely to come out with the air, at which point you have just squirted God alone knows what liquid onto your precious sensor.
Get a bulb blower if you want a relatively non-invasive technique. These are cheap and wont through rubbish at your sensor (unless you use them in a dusty environment, but its pretty obvious you do it somewhere as dust free as possible right?).
If that doesnt shift it there are a lot of cleaning solutions on the market