An easier way than trying to "scrub your game" would be to temporarily rename any .dbc file in your DCCache folder to another extension. (I usually do something like change it to .dbcbackup.) If it disappears, then it's in one of your .dbc files.
If you then want to completely remove it, it may take a bit of work, but this is my suggestion:
Rename (or temporarily move) all your .ebc files (those are your store content) to another folder.
Rename just ONE of the .dbc files back to .dbc.
Check the launcher (under Installed Content) and see if the item appears. If it does, delete it from here. If it doesn't, go to the next step.
Rename that .dbc file to something different, and rename the next .dbc file back to a .dbc extension. Repeat step 3.
It might take a bit of time, but you can remove the cc from your game that way. That, btw, is the only way to remove that Arezzo counter completely from anyone's game.