Turning off "Accept cookies from sites" and turning it on again.
When turn off "Accept cookies from sites" and turn it on again, "accept cookies from third-party sites" changes from "never" to "always". It's not comfortable.
Todas as respostas (2)
There are many "cookies" extensions available for Firefox that modify or extend the features that are built into Firefox preferences. Look for one that has the features that you would feel more comfortable with. https://addons.mozilla.org/en-US/firefox/search/?q=cookies
That sets network.cookie.cookieBehavior to 0 and that enables all cookies. You would have to toggle network.cookie.cookieBehavior between 1 and 2 to keep third-party cookies disabled (3 = visited)