For anyone using Firefox, as soon as Containers became available outside of Nightly, I created one just for Facebook. Is the "Facebook Container" any different than what I already made?
The extension also cleans up Facebook cookies from your other containers. This extension is what got me using containers, but I deleted it after I realized it doesn't do anything after the initial installation.
Edit: Apparently this extension also prevents you from opening other sites in the Facebook container.
I mostly use it to manage the 3 google accounts i use daily