How to check for duplicates in a Document Tray

So I've got loads of documents in a tray and *without putting them in a file cabinet*, I want to filter for duplicates of a single field so I can find and delete them. Is there a way I can do this

As they are in the DT we cant really use the indexes yet. You could create a FC with the indexes and store all the documents. Then you can search for your duplicates/delete then migrate remainder to the original destination FC.

Just an idea, probably a better way.