Don't work with anything other than Google. In other words, it is useless.

Got the extension to hide Aliexpress from search results.
Added Aliexpress as well as Alibaba to the blacklist and...
NOTHING.
Extension would allow the searches and when clicked on the link it would let me go to the site.
When clicking on the extension in the toolbar it would ironically show "Unblock this site"
It was NEVER blocked!
Useless extension that does not work!

Does not work. I'm on latest firefox with ecosia.

With the new (in beta) google search 'option dots' at the right hand side of each result, this no longer works, sadly. There's no way to opt-out of the beta features (it seems to be a soft roll-out on google's end.)
It's my hope that this addon will be updated soon, as I love the features it provides. If there's any more info I can give, let me know.

Google's updated their search engine scripts or codes, i believe. As seen through July 2023, the ublacklist dialog has gone missing under the url where it has been always. What was blocked still appears in results despite. Browser wasn't updated, so that's not the cause. There is no way to block them at the moment. Please fix this soon.
Updated: As of early March 2026, I've seen a different change. You can block them in Google's search results but not immediately. There seem a bug where each time you want to block any site, it won't be active until you click the extension button to activate it. It isn't as automatically active like before. Each time the page is reloaded/refreshed, the extension will require to be clicked first in order for the sites to not show up again. I believe this has something to do with "Only when clicked" shown when the extension icon is right clicked. It is the only already auto selected option placed and there are no alternatives. Why is that even shown then?
This has become an annoyance yet again.

You should add the "pause blocking" button.