Since unlisted videos don't appear in YouTube's internal search, third-party databases act as a crowdsourced archive.
After testing 14 different extensions, the only one that reliably helps you "see unlisted videos" in a legitimately useful way is: see unlisted videos youtube extension
Only install extensions from the official Chrome Web Store or Mozilla Add-ons site that have >500 users and >4-star ratings with recent reviews. Avoid GitHub-hosted userscripts unless you can read the code. Since unlisted videos don't appear in YouTube's internal
While you can't search YouTube's database for these, you can often find them using these methods: 500 users and >