Geeezus, sometimes it's just too easy to feel like an idiot when you have a tool at your disposal that you're just not thinking about due to a lack of usage.
Got into the MX user manager, chose to delete a user account, namely the citrixlog account, logged out of the system and then back in again ... PROBLEM SOLVED ... the citrixlog user is gone.
Let this be a lesson to myself and anyone else who forgets about the wonderful MX User Manager within the MX Tools section.