Cleaning from the outside can be counter productive, as instead of blowing stuff 'out' of the device you would be blowing 'into' the device.
It would definitely need to be opened to get cleaned out. You may want to check for videos online on how to open your particular model. There are usually good ones. Just be careful when doing so.
Also, be sure that the device is not under warranty any longer before you go and open it up. If you do, and it is under warranty still, you can void that warranty. If that is the case, I would contact the manufacturer about a repair/replacement.