Hi Entropy,
here is a shot taken of Eta Carinae through the horrendous light pollution south of me over Parklea and Blacktown, I can attest that the Eos clip filter works wonders with heavy light pollution in Sydney, just take a shot of a white piece of paper in clear sunlight and set this shot as the custom white balance in the camera and the blue tinge you normally get through this filter will disappear.
https://www.dropbox.com/s/lh28wc80c3...ilter-test.jpg
Well worth the money and so convenient to use
Cheers
Chris