Sadly 3 stars because
- each time I go to fb, tab often not being put in a container
- having to set cookie policy each time
- having to login each visit

Using in conjunction with add-ons Fb Container and Temporary Containers.
! You need to know the sequence though!
Add Fb Container add-on first.
DO NOT add a fb container to Multi-Account Containers (MAC) it stops Fb Container add-on!

Today I noticed a tab is on fb and is not coloured (not in a container) I disabled and re-enable Fb Container add-on and it immediately contained the tab.

The fb container I made in MAC keeps reappearing - removed fb from its site list but keeps reappearing in MAC. Will probably rename and add other sites to its site list.