Exchange 2007 Public Folders Duplicates

The company I work at runs Exchange Server 2007. Users here store everything in Public Folders.  The size of the Public Folders Database is now around 270 Gb.  Using Outlook to troll through Public Folders shows that  often multiple copies of the same email with the same attachments have been filed into Public Folders by different users.  We're talking hundreds of duplicate emails and attachments creating a huge amount of bloat in the Public Folders database. I'd like to get rid of all of the duplicates - keeping just one copy of the email and attachments in the appropriate Public Folder. Has anyone run across a tool/script that they have successfully used to clean up these duplicates? Also, it would seem to me that once an email with an attachment is filed into Public Folders, Exchange duplicates the attachment instead of keeping a single copy in the database, is that correct?