We migrated search heads and there was content in user directories from users that have since quit, and therefore no username got created. I get a message that there are orphaned searched. Any advice?
If you can't use the re-assign objects interface for those searches, then i would suggest either deleting savedsearches.conf from the user ($SPLUNK_HOME/etc/users/the_user/some_app/local/savedsearches.conf) or just delete the user directory all together. If it's shc, you can do that on each member and then a rolling restart.
Of course, first ensure those searches should no longer be running. If they should still be running, then just recreate them yourself.