I may be jumping the gun here. I literally installed this add-on five minutes ago. It didn't have the specific feature I was looking for, but it seemed to come the closest.

I do a YouTube search. I see a bunch of relevant videos. Then I start seeing stuff that have nothing to do with my search. Then the foreign language stuff shows up and pretty much overtakes my search. I wanted to stop all these videos in languages I don't understand from showing up in my searches.

I had just done a search that was typical of the problem. Good stuff, useless stuff and foreign stuff. The further I scrolled down the more foreign stuff there was. Then I installed this add-on and ran the same search. I scrolled down and down and down. Not only was I not getting tons of irrelevant stuff, but no foreign language stuff.

Okay, it's not perfect. Keep scrolling down and foreign language stuff does start showing up,but it's a lot better than it was.

We'll see how it functions in the long term, but for now I couldn't be happier with Unhook.