Doesn’t work
Looked promising but it just doesn’t work. It found 28 duplicates in my photo library (even though there is clearly hundreds), and deleted them. After that, I opened iphoto and deleted the duplicate folder where the app trashed the duplicates. Rerunning the app found the same 28 duplicates. I turned off icloud to make sure the photos were not getting replaced, reran the app with the same exact results of find the same 28 duplicates even though I deleted them from the folder.
capegreg about
Duplicate Cleaner For iPhoto