there is a very same addon for firefox called cookie quick manager when you installed it, you could protect cockies of intended websites and kill the others.
But there is still a question, why not using
tor instead of
By using tor which you can install in your distro and route your network traffic through
tor network, besides you can use Bridges.
Also, you could even use your firefox without any thinking about using tor-browser, and that's possible via traffic director addon in firefox called Switchy Omega.
So when you want you can handle your packets to be routed without tor (directly) or packets routed through tor profile you can move over a box in the addon.
Even better you can add conditions like if you want website x to go through tor and but not y, you will have only to add a condition to the tor profile in the add, believe it or not, it's super simple.