Your advice seems pretty good. But I just want to make sure I have this right. It sounds good to me. But it doesn't hurt to have another opinion.
But in this particular example, there are 3 wires on the Leviton 6287 noise filter.
1. Black load
2. Black hot
3. White neutral
Again, correct me if I'm wrong. This can and does get confusing. Especially when you have 4 sets of joining wires to keep straight: The switch's, the filter's, the ballast's, and the power source.
But a basic principle should be to follow this sequence when hooking up a filter. (1) Wire the black power source to the Black(hot) line of the switch, (2) Wire the Blue load line of the switch to the Black hot line of the filter, (3) Wire the Blue/Black load line of the filter to the Black line of the ballast, and then (4) Wire all the White neutrals together: The switch's, the filter's, the ballasts' and the white from the source (breaker box, or whatever).
It took me awhile to think this through. But that sequence should filter out problem causing noise from the ballast to the switch while leaving the path unfiltered from source to the switch. I can understand why people get flustered hooking up X10's.
I would think the same principle applies with a plug in switch. You would just have to use a voltmeter to see which wire is actually hot and actually cold. I've seen some crazy things.
But that appears to be ok. But any input either way would be appreciated.
Hank