Easy way to tell which graphic templates are unused?

We have a project with large number of graphic templates, some of which are unused. I’d like to delete the unused templates.

Is there a quick way to determine that a graphic template is not referenced at all in a particular project?

The quickest way will be to use the Find/Replace feature of the designer. It can be found under the Edit menu. Search for the name of the template with only ‘Windows’ checked, and be sure to search ‘All Windows’.