The only way I know Trev is a sealed CCD camera. That way the dust collects on the glass not the sensor. The DSLR is very vunerable to dust and grit as without their lens and they are open to all sorts of nasties. Perhaps there is some sort of UV/IR filter you could use to seal the camera and still attach a T thread?
I keep my 40D without the lens on but the body cap on , and I wrap the camera up in the soft fabric that came with it and in a closed camera bag.
Avoid using compressed air to remove dust, if can force the dust deeper into the camera and crevasses within and between bits.
A lens pen is the way to go, or simply blowing on it to dislodge dust.
I keep the lens caps on my lenses at all times unless I am actually using the lens , and if came with a case , it stays in the proper case.
My 40D has a builtin ultrasonic dust cleaning routine that is automatic when the camera is powered up.
I NEVER EVER touch the camera's internal filter or the sensor.
