Strangely, the cookies this addon claims to delete still appear in the Firefox preferences and in Ccleaner. On the other hand, after I close a tab and wait for CAD to delete the tab's cookie I have to sign in again on an account which would indicate the cookie really having been deleted. However, I assume Firefox does its part on this problem because even though I select those options in the preferences that delete cookies after closure I still find all those cookies in Ccleaner after I close Firefox. The problem with this addon is basically the same, even though it says that it deleted a number of cookies, the cookies apparently are still there, I can see them in the Firefox preferences or in cleanup tools like Ccleaner. You got an idea, dev?