The Facebook Container Extension is available to use with Firefox now, and once it's installed, Facebook will be housed in its own "container" each time you visit it. You'll see blue lines around Facebook indicating that it's in a new container tab, but everything will still work as per usual.
Once installed it'll automatically delete any of your Facebook cookies and log you out of your account. Clicking on a non-Facebook link while browsing Facebook will open it in a regular tab, and clicking on Facebook Share links in regular tabs will open them in the Facebook Container.
"If you use your Facebook credentials to create an account or log in using your Facebook credentials, it may not work properly and you may not be able to login. Also, because you're logged into Facebook in the container tab, embedded Facebook comments and Like buttons in tabs outside the Facebook container tab will not work. This prevents Facebook from associating information about your activity on websites outside of Facebook to your Facebook identity. So it may look different than what you are used to seeing."