Deleting multiple variations at once

In my workflow to finding new sounds/tones, I find myself heavily editing an existing rackspace as a starting point. If I get something I want to keep, I duplicate the rackspace, and then go back and use the ‘Revert rackspace to last saved version’ on the original rackspace. This all works nicely.

However my new rackspace obviously has all the variations of my original. I want to get rid of all of them except the one I had been on when doing all my edits. It would be nice to be able to CTRL+click or Shift+click (or Shift+arrow keys) to select multiple variations and delete them in one go.