Bypass any future tit for tat revoking of clearances by an executive order (and then legislation) revoking everyone’s access when they leave one job and nove to another within government. They’ll have to get it recertified is all.
Revoke the clearance of everyone leaving government until they actually get another job requiring a clearance. Then, if good behavior, it can be easily reinstated.
Better yet, we need a Tyburn Tree style scaffolding to hang the traitors a dozen or more at a time.