Unfortunately, this forum allows inluding links to attachments in your posts. The result is that most users who could help you will NOT use them because it's too dangerous. The normal and safe way to show your screenshots and images is to 'embbed' them in your post, using the 11th icon on the icon bar above your post.
I am afraid you can't rely on the visual search in the organizer nor on external duplicate finders to get what you are expecting. The main issues are:
- the definition of a 'duplicate' (not only same name...)
- the fact that an external search will create 'missing' files in the organizer if it even can help you choose among the duplicates
- the fact that finding and 'stacking' the duplicate set does not help you to choose the one to keep.
So, my two personal rules:
- rather find the reasons for duplicates rather than trying to delete them
- stacking files is already an efficient way to manage duplicates rapidly when browsing in the organizer. The spoiled disk space is not a major issue with catalogs today. Better having an efficient browsing tool than a 'clean' folder organization.