Set white balance for all selected files?

Is it possible to select a number of files and then set white balance for all of them? I'd guess that this would mean creating 'sidecar' files for each of the selected files - which might not be fast.  And the app is named FastRawViewer, so I may be looking for something that isn't there.
Use case: I use UniWB so my RGB histograms give ma a more accurate idea of my exposure. I also use a grey card, unless I really know what my light color is. So, I'd like to be able to set all selected files to a particular white balance and get rid of the green cast while I'm evaluating (and to carry that WB into ACR).
I'd hope to be able to select a number of shots, right click one of them, and see "set white balance" as an option, with, possibly some sub options, including "select grey".
Yes, I'm aware of the "make WB same as previous" option. I'm also aware that I can set WB on a number of files in Bridge, but I would much prefer to do this in FRV and dispense with Bridge altogether.