I created a final cleanup action group to remove extended tags that are not needed for our operation. After applying the action, and viewing the extended tag listing, the tag is still there. I can manually remove the tag by deleting it from the extended tag list.
You do not show us the action so I just make a wild guess:
To delete a field only enter its name without the % characters around it (which would refer to the contents of the field). But you may have taken care of this already.
