Bit of a tip and don't recommend it or say it works 100% (Disclaimer!) but my camera had managed to get dust in it no surprise there from living in the Philippines but it was on every photo. So after not enough time to get it professionally cleaned in the UK and Oman's nearest store being miles away I was pondering in the mall when I had an idea in the computer hardware section. I bought a can of compressed air (the computer cleaning air). Fired it into my camera and it done the trick. Have to bare in mind if it hadn't of worked was going to replace it as I was tired of being unable to get some decent photos while in Oman. But did the trick and its worked fine ever since. Just don't tilt the can as it can cause a freezing liquid to come out.
Read this somewhere else once before, it can work but can also cause the dust to just shift about and stuff. I guess if you are too far from someone who can clean the camera then this is perhaps the second best option..
Patience had worn extremely thin after traveling from the Philippines to the UK and now into the Middle East to find my camera was US. Glad it worked but your probably right if you get it at the wrong angle it will blow it further into the camera.
