I see the most recommended treatment /du jour/ for the vexing "dust
specks on sensor" with digital SLRs is a brush that is charged up by
spraying it with compressed air. Problem is, the company selling these
brushes is extorting money from people, IMO, by charging around $100 for
an item with a manufacture cost of pennies.

Their website (http://www.visibledust.com) states that an ordinary nylon
brush cannot be used for the following reasons:

"Sensor Brush™ has been designed from the start specifically as a
cleaning tool for delicate objects. There are many types of brushes in
the market but they are not designed to be sensor-cleaning tools. For
example, glues used in traditional brushes are quite destructive to the
surface of the ND filter glass or cover glass. The polymers contained in
many traditional brushes will cause a fatigued look on the glass due to
the staining of the sensor. There are also many deformities in the
brushes that are not visible by naked eyes. They can cause severe damage
by creating microscopic scratches, which after accumulating overtime
will create a fatigued look or catheter vision. We have done a lot of
research in these brushes to bring the highest quality products made for
the exact purpose of removing dust from delicate objects."

I think this is absolute hogwash!

- The glues used in synthetic brushes are in the ferrule, and will never
contact the sensor surface.

- Polymers (plastics) "staining" the sensor from an occasion light wipe
on the surface? Balderdash! Maybe -- MAYBE -- if you let the brush rest
for months against the sensor cover (also a plastic), some interaction
may occur, but I doubt it.

- Deformities in the brush not visible to the naked eye?! LOL! I have
inspected a typical nylon artist's brush with a microscope and I see
nary a "deformity" anywhere.

This "Sensor Brush (TM)" product will surely go down in the history of
photography as one of the worst scams of all time. How we are all going
to laugh in years to come!

I encourage everyone to go to an art supply store and buy a high quality
nylon brush for a couple of dollars, and a can of compressed air. Voila!