When I was little, I used to suck my thumb all the time. And it wasn't just a temporary thing. I was addicted for quite a while. There wasn't anything that could stop me. Trust me. My parents tried everything. Nothing worked.
Until the orthodontist put a permanent retainer in my mouth. It was literally glued to my teeth. And when that didn't work, they put spikes on it. Seriously. Spikes. But, hey. It worked.
It's crazy to think that something that sounds so ridiculous worked. But the only thing that would keep me from continuing the addiction was to make it painful.
Maybe I should have learned from that...