Clearing out old discarded data

I have a project that has grown very very large (about 5.5GB), despite the (nearly) end result being only around 2 minutes. There’s around 15 tracks, but with various short clips scattered around each of them; there’s only 2-3 overlayed at any given time, including muted. There’s essentially only around 4-5 minutes of audio here, but the size is enormous.

I think I know why the size is so large, and it’s because all these short clips were done by importing various much larger files, cutting out the part that I wanted, then deleting the imported “source” track. Had all those other files still been part of the project, the 5.5GB size would make perfect sense.

I removed all those larger sources thinking that they wouldn’t be a part of the project file, but it seems like they’re still there, buried within somewhere. I can’t access these files within the UI once they were removed, and I can’t access them through undo history anymore since Audacity clears that when I close the project. They seem to still be saved, without any tangible effect.

How do I remove all this old “dead” data from my project file? I’ve seen my project get compacted on saving, it doesn’t seem to have much effect. Is there any way to remove this without flattening down my whole project permanently, or copy-pasting each individual little clip into a new project?

Looking at this reddit post, it appears that when I would cut and past a section from the source file into another track, it would copy in the whole source file, start to end, and just “resize” it to my selection.

Attempting to “resize” a couple of my cut-and-pasted clips (beyond what I thought I had) confirmed this. This was what I did for nearly all my clips (some I set clip boundary in the source before copy-paste, but not all). So since cut-and-paste into a new track is a nondestructive edit, all those “source” files are in there, in full, some multiple times.

Follow-up then, is there any way to quickly set the boundaries for every clip I have, in order to “prune” the old data out?