It's a pretty shitty trick to have a "friend" on fbook and unfollow them. I mean, this "friend" happily posts stuff and thinks there are actually people in the universe that might give a rat's fart...but no! They've been "unfollowed". But of course, still "friends".
I use the "stay friends but unfollow" trick on people who keep sending me friend requests after I remove them. I got a guy like this, I can't seem to shake him so I just make sure he doesn't interfere with my time.