Seems you would have to go through and manually delete all the morphs that do not belong to a particular body part. Maybe a script could be written to automate that, but the script would have to know which morphs belong to which body part, I'd imagine.

After upgrading to SR3, when I go to delete a morph from a body part, a hierarchical list appears containing a check box for every body part that has the morph. Where before it was tedious, it is now quick and easy to clear morphs from the parts where they don't belong.

Download my free stuff here: http://www.renderosity.com/homepage.php?page=2&userid=323368