white balance using grey cleaning cloth ?
 

Has anyone tried using this cleaning cloth ? It may be easier to use than a white sheet of paper or a real grey card.

http://www.bhphotovideo.com/bnh/controller/home?O=productlist&A=details&Q=&sku=220482&is=REG

Microstar MIC-FIB CLEAN CLOTH 7-7/8x7-7/8"18% GR
$3.95
The Cleanstar Micro-Fiber 18% Gray Cleaning Cloth has a 50/50 blend of polyester and nylon which makes this cloth more moisture absorbent than other microfiber cloths.

This cloth is specially made for the photographic industry, this convenient cloth is the exact color of an 18% gray card. This dual purpose cloth can be used both as a cleaning cloth and as an 18% gray card.

It's the best cloth for cleaning eye wear and lenses, it leaves them spotless and doesn't scratch, streak or smear.

Dimensions: 7-7/8 x 7-7/8"

Why not try it out for $3.95? Not that expensive. If you do, please
report back here how well (or not) it works. Thanks!

Ok. I will order with my next set of camera supplies, though that may be a few months.