How to remove unused parts from an Allegro 16.6 PCB file

I have an Allegro PCB Editor file that has a mechanical part that was added but then not used.

But the IPC output refuses to complete because this unused part still exists in the PCB editor file database, even though it is not used. Dbdoctor refuses to remove the part! How can I clean up the Allegro PCB Editor database file to only have used parts stored?