Bulk Delete for files , and don't default to ADO integration - Attachments

Whoops. I accidentally set up the ADO integration to include attachments, and now I've got hundreds of ADO development files in my beautiful AHA portal "Workspace Files" section.

I've now switched off the attachment synchronization, but left with a 100+ files I can't bulk delete. I have to click into each file individually, then find the associated feature/story, and then delete the file.

This painful process works for most files. It doesn't work for SQL and JSON files that have been synchronised from ADO. I can't find any way to track these down to a feature, so that they can be deleted.