Just click Black & White. You cannot create with a filter what's not there in the first place.
When you filter out all of that specific frequeny, no normal color information will remain. You'll only retain the contrast information (which you can bump nicely with Clarity).
P.S. I think something went wrong with your Caps Lock or Shift key, maybe you should check it for glue or chewing gum.
Just shoot a grey card under that source and white-balance... and then refine it with the white-balance tool in LR.
I am amazed at how a lousy looking .nef file will look in funky lighting like you describe and then clean-up with the white-balance.
If the filter only removed the specific frequency of the sodium vapor then everything else all the other color frequencies would remain
probably best on the lens and maybe can't do with the three color sensor but these IT guys do amazing things.
they do that with audio all the time to filter out noise
Good idea I was thinking the same thing with a white card but that would color correct the image but not cut out the yellow orange noise
pulling down the sliders in LR eliminates 90% of the glow but if it were more specific then could really cut through the noisy sky
I going to try taping a CTB gel and test it out next good night
Later I realized that changing the WB doesn't change the RAW file anyway so I went back to finding a dark place
but instead of a meteor shower we got a rain shower instead LOL