I used this product with some trepidation after reading of difficulties with smearing etc. After following the limited instructions carefully this product worked wonderfully on dust spots that had resisted removal using a simple air blower.
Job Done.

By Munster Mad from Boston, MA on 8/18/2008

I bought the NEW Arctic Butterfly® 724 (Brite) Sensor Brush as it was recommended on a number of sites. The packaging, leatherette outer pouch and inner plastic hard case, were very impressive looking. The product itself is cheap and flimsy looking. The switch to activate the LED and rotate brush looks like it is not designed with reliability in mind – guaranteed the MTTF is very low!! The brush was of very poor quality and all I succeeded in doing was moving the dust, already on my sensor, from one location to another (the brush is meant to charge, after rotation, and attract dust particles away from the sensor onto the brush fibers) I followed ALL instructions to the letter, multiple times, but to no avail. For $100+ I would expect a lot better i.e. I would expect that the product would work!! [@]