No, it was all done within youtube or google. I was quite surprised, but it did work. 
No 3d-party extensions.

I don't think YouTube would allow you to do that as Google is an advertisement company.

What you are referring to in your comment is simply to not base the recommendations on your history. If you disable it, then it still shows you recommendations, but not based on your history.

Most probably you installed a third-party browser extension.

nullama

tech

Recommendations currently suck

satan

You can disable Youtube recommendations. I did it recently. My feed is just empty now, it's great. I don't watch mindless videos anymore unless I get a direct link to them or look for them actively. Don't remember how I did it, but maybe [this can help you](https://support.google.com/youtube/answer/95725).

```
Turn on or off watch history

1. Sign in to your Google Account. 
2. Go to myactivity.google.com. 
3. Click YouTube History. 
4. Click Turn on or Turn off.
```