That's a good question swise. I was thinking about it, but I don't think it works like that, since ions follow an exponential decay (for stable and unstable ones). Everything that exists has some form of polarity, even noble gases (think van der Waals). Even if you did use all those cloths, the magnetic field exists beyond the screen and it's still going to attract the dust. Basically you're fighting a losing battle unless you live in a clean room.