After trying a dozen addons like this when youtube changed a few months ago and made them stop working, I found this one and its excellent. Does exactly what I want and hides channels I don't want to see. It stopped working a few days ago and was fixed in less than a day. Absolutely recommend this one, check it out.

Thank you for making this extension

Fails to block some filtered titles even though the filter keyword is exactly as it appears in the title - case and all.

UPDATE:
It is possible that another extension (which I have since uninstalled) could have interfered with this, so I'll up my rating from 2 to 4 stars.
I stick to 4 stars and not 5 as the filtering is fairly limited compared to some other extensions I've used before but are sadly no longer being maintained. Regex filtering would have been awesome.

Works very well, thank you for your contribution...

Easy and explainable screenshot, and fast language shift to get ahead of the understanding.

Very well done <3

素晴らしいです！凄い快適に使えてます。
老舗のChannel Blockerが使えなくなった人は次はこれを使いましょう！
制作者様（日本の方？）本当にありがとうございます！助かりました！