If I've understood correctly, it might not be necessary to isolate everything in different containers. As long as you block social logins using an adblocker, the total cookie protection in firefox shouldn't allow websites to know what other sites you're visiting.
the test is to go on ebay and search for something specific, and see how the advertising changes when you navigate the web.
It might be overkill, but I am old enough to know that sometimes you need to use a sledgehammer when a normal hammer might work ok.