After two and a half years shooting mainly digital and well over 100,000 images, I seldom have time to a deep cleaning using a swab and cleaner, except after spitting or sneezing inside the camera;).

I have shot in dusty rodeo arenas, at fires, and in the windy desert and change lenses more than I did with film cameras, especially since D-cameras run 3-5 times the price. Just can afford a separate body per lens.

I do get some dirt, but fixing is generally quite easy with the healing brush.

Never had luck with a syringe and nearly always use the dreaded canned air. But be warned that what works for me, could destroy your camera.

The way I use it is to be totally sober with a fresh battery. Ever so carefully blow out both the mirror chamber then the sensor with the camera set on bulb. I have five cameras that I clean this way which is a necessity since electricity is sometimes unavailable to me when I am in the field.

After shooting 600-800 pix during a day on the road for weeks at a time and dead tired after starting at daybreak and downloading and editing the last pix, usually midnight or later, this has been my most consistent way to keep the sensor clean. It works for me, but I don't recommend others trying this. Don't blame me if you screw up your sensor! You are on your own and have been forewarned!

As Ben reiterated, don't try this at home with that "dreaded" canned air!