I woul first try a can of compressed air, you can by it from places like Maplin or Tandy or your American eqiv. Just remove the battery and open cd/dvd draw first to protect the lense and spray through vents both ways. Make sure it's in short bursts or the air temp may drop to freezing and damage something. It's worked for me in the past and it's cheaper.
The laptop must be cool before doing this,