I've wondered if this works, myself. I've thought about trying that tactic--pretending to LJBF a girl before she gets a chance to do it to you for real. Of course, it wouldn't be a good idea if she was showing clear signs of interest. But would she actually try to prove that she could be something more, or would she just accept the idea that you see her as a friend and never challenge that? It's hard to tell if you're not just setting yourself up for failure. She has to really think you're worth pursuing to go through the trouble, and it's not like you're the only guy she knows. Using such a tactic assumes that most of the guys she comes into contact with are AFCs. However, she may have several male acquaintances who are better looking, more outgoing, flirtatious, who have that "attitude", that she wouldn't hesitate saying "yes" to. By the time you've finished playing your little game, she may already have a new boyfriend.
Still, I wonder about trying something like that, and if it would actually raise a womans interest. The idea behind this method is that by LBJFing a girl, she may start to wonder if there is something wrong with her if you are not attracted, and try harder to prove you otherwise. I can see the reasoning behind it, but I still wonder if a girl would actually do something like that, or if she'd just accept it and move on to someone else.