duplicate elimination in iPhoto

Does anyone have a rule which will search the photo folder for duplicates and move them, either to another folder, or to trash, or just delete them?

At least with some versions of iPhoto, there might be risk using Hazel or other methods for deleting duplicates directly from iPhoto libraries. Here's a warning from the developer in Duplicate Annihilator comments on 06 Dec 2008 at MacUpdate:

Messing with the files in the iPhoto library package or folder may cause a corrupt iPhoto library database and or loss of data.

Even without risk Hazel may not be a good tool for this task. Which condition(s) would trigger deleting duplicates and what criteria would be used to determine which files they are?

I don't have experience with specialized apps like Duplicate Annihilator or Duplifinder to know if they're worth paying for.