I recommended WP Media Folder on a Facebook WP group in response to a question. An interested person asked this question, which I did not know the answer to. I'll pass along to him your answer. The question seems to have nuances. Thanks.
"Quick question. I'd buy this in a flash if I knew it could give an accurate presentation of images that are TRULY unused. I've seen numerous plugins that present images as "unattached" - when they are in fact still referenced by internal links.
Some of this comes from the technical definition of "unattached", which apparently doesn't explicitly account for Featured Images (an image can be classified as "unattached", even when used as a featured image).
Worse still, even the regular WordPress filter for Unattached is currently listing images that I use - in a normal way - in public posts. If I delete those images I break posts. Weird.
So, to my question... do you happen to know if this plug in can present a list of images that are REALLY not used from post or page on my site? I'd pay for that."