If you are afraid to clean your sensor because of all the manufacturers warning, you can test your procedure (whatever it is) on a multicoated filter. Any greasy film, crap from the air source, bad techniques, etc will show up very easily on the surface of any multicoated filter. They are very sensitive to the least little anything.
The manufacturers are concerned about owners cleaning their own sensors for a very good reason. Have you ever bought a used lens that looked like the previous owner had scoured the surface with a Brillo pad? I remember my father obessively cleaning his lenses at the drop of a hat. It wasn't until I was I became involved with professional astronomers who have extremely high demands, especially with regards contrast, that they thought nothing of a layer of dust on their optics that I would have previously not tolerated. A little dust that is not near the focal plane doesn't do anything except lower contrast a little bit.
That being said, dust ON the optical plain shows up very clearly especially at small F#. But if you can clean the surface of a lens without damaging it, you can do the same for your sensor. Remember, you are actually not cleaning the sensor directly, but instead the surface of a coated glass IR filter or AA filter. This is not any harder than cleaning a lens except its in a hole with a shutter that wants to close on your brush if your not careful!
Any grease free brush will work. Finding one is the subject of a long thread. Thats why people pay too much money for the Arctic brush. It IS grease free, however.
Dont worry. be happy
Rex
