Pron Filters?
Since most of our ISPs now give us Pron Filters how about they give us FaceBook Filters using, for example, the list from...
https://qz.com/1234502/how-to-block-facebook-all-the-urls-you-need-to-block-to-actually-stop-using-facebook/
Non-technical people would just visit their "I want Pron Page" and click the check box for "Block FaceBook" in order to go dark.