How can I get rid of this context menu option?
From: http://www.reggieashworth.com/appdelete


  AppDelete keeps a .workflow file to provide a contextual menu item for convenience. If ever removal is required simply delete it from your /Library/Services folder. Or on Leopard your /Library/Workflows/Applications/Finder folder.


It appears you should be able to remove that menu item by deleting an item from one of the afore mentioned folders depending on which OS you have installed.