Best Practices for Session Cleanup

[groovilator]

I'm nearing the end of a rather dense project and I'm ready to begin ridding my hard drive off all the excess data that will never be needed again.
So I'm doing things like consolidating tracks, removing unused files, trashing rendered files and old sessions, etc.
One big issue I've had with this project, in particular, is that I'm having to freeze tracks on literally everything because my computer isn't fast enough to handle this software. That has caused a major conundrum in keeping my hard drive clear because those rendered files don't go away after you unfreeze, they just accumulate.
So for my first session cleanup I made a copy of the final session and 'committed' every one of the tracks to make it permanent. Then I went back to the other session and unfroze the tracks before emptying the Rendered Files folder. Then I consolidated all the audio, selected the unused tracks and deleted those.
(That way I have a copy where everything is permanently printed to audio and another where I just have the wav files for any future remixing.)
But there are still file fragments in the list even after getting rid of all that stuff. Even though I deleted all the inactive tracks that were still lurking in the track list. Because of that and one other weird thing I won't bother describing right now, I feel like there may be a more methodically designed step-by-step process for this major cleanup task and I'd like to get some feedback on this before I proceed.
So if you have a tried and true process for this, please post away!
Thank you!