It _has_ been discussed before: I just found a 2007 paper about dust problems in lunar living environments; the suggested solution is a magnetic air filter. The

It _has_ been discussed before: I just found a 2007 paper about dust problems in lunar living environments; the suggested solution is a magnetic air filter. Their solution is different of course (I was simply brainstorming about the powdered domains solution - there are many ways to magnetically filter particles from the air): "DUST MITIGATION: LUNAR AIR FILTRATION WITH A PERMANENT-MAGNET SYSTEM " http://www.lpi.usra.edu/meetings/lpsc2007/pdf/1654.pdf http://www.lpi.usra.edu/meetings/lpsc2007/pdf/1654.pdf There are probably many more such ideas published.