In Xcode is it possible to build a clean version of my project and remove any saved property lists associated with it?
I'm refactoring my code constantly and the old property list that gets saved is causing my app to crash because the data has become old and rotten.
If you mean that you have an app installed in the simulator with data in its documents folder, then not that I know of. The easiest way I've found around this is to go into ~/Library/Application Support/iPhone Simulator/{SDK version}/Applications, find the folder for your app, and trash it.
You can also go to the iPhone Simulator menu and select Reset Contents and Settings...