Ugh … figured it out. Similar to FUNC + press LEVEL/DATA to unload from the RAM, that also works on the sample locks folder (and is not referenced in the manual @eangman).
To get out of my problem, I had to make a list of samples that were in the lock folder, delete from that list the ones that were REALLY used in trigs, then unload those from the sample locks folder and ALSO unload them from the RAM folder.
That seems unnecessarily complicated.