[Alphaeus]

In my experience, blocking entire channels rather than individual videos is much more reliable. Clearing out related videos from your watch history also helps a lot.

[timbit42]

I use the web browser add-on, "Channel Blocker", to block channels. It puts an X next to the channel name. Clicking it permanently removes that channel's videos from every YouTube page.

I use, "BlockTube", to block keywords in video titles and channel names so those videos never show up in searches.

I use, "Unhook", to remove recommended videos from YouTube pages.

I use, "YouTube-Shorts Block", to block shorts.