Encore Project Cleanup

I posted this over on the Adobe Encore forum but didn't receive any responses. Hopefully someone here can offer some feedback.

I'm working on a Encore DVD 1.5 project in which I've added and deleted several audio and video assets over the past few weeks. Now that my DVD is complete, I've noticed that my Encore "sources" folder is becoming bloated with many unused and redundant files. My project file structure is as follows:

Project.ncor
Project - Cache
- Sources (this folder is bloated with old and unused copies)

Is there some way I can perform a Encore project cleanup and get rid of the unused bloat?

Any help is appreciated.
-AJ