Abandonware. This extension isn't compatible with Youtube anymore and should be either updated or remove.

It didn't work for me.

I doesn't work. I mean it doesn't even start.

неработает

Doesn't work.

Doesn't work. (Even after following the instructions about going to the WL page and pasting the URL provided).

doesn't work 🤷‍♂️

It does sort of what you think id does. It deletes ALL videos from the link, watch later. Not just the watched. I've installed this add-on only cause youtube has removed the "remove watched" function.