I tried these approaches, but it never worked for me. I find the best way to kill these things is by breaking the things that make them addictive. E.g. I unfollowed (not de-friended) everyone on Facebook. I can still use it to send/receive private messages and organise events, but my newsfeed is totally blank. I now never go on Facebook unless I have something to do there. After a month or so the stimulus-reward loop was removed from my brain.

I use browser extensions to block the tracking side of things, uninstalled the apps from my phone, and I'm now pretty happy with my relationship with Facebook and the impact it has on my life (~0).