Smokin Paul and others
YES the URL MECI filter I referenced, stops X10 in its tracks. You need to place the filter AT the noise source with any X10 control between the line and the filter.
Internally the can is a low pass, L-C, PI filter. Each line has a series inductor, so I don't think phorce1 is correct in thinking it would be good to 30 amp, since full 30 amp would be going through each coil when used at 120V.
I have never o'scope'ed the filters response, and component values are not shown on the can, but I bet roll off is faily steep after a kilohertz or two.
As far as the $20 minimum order..."MECI", "Electronic Goldmine", "All Electronics" etc, have so much neato stuff that I got 20 bucks spent by the time I get to page three of the catalog(s). I had not even thought about the minimum order limit when posting the URL. Sorry to all.