Doesn't always work. I've actually been using this addon from nearly its beginning. I've advocated for it online. However I've noticed that recently it will not get rid of some cookies. Reddit cookies in particular like to stick around, and I do not have reddit whitelisted. I'm not a developer and so I cannot fathom why it's keeping these cookies when it's supposed to remove them. It keeps them even after browser restarts. Also the extension's menu doesn't fit in its little box and so you have to scroll to read it. It's time to try a different addon.