Didn't realize that
David,
I had always thought that the leg work was illegal in competition, like Judo, I didn't realize that it was just a "don't practice because of injury possiblities" thing. Personally I can take or leave heelhooks. I've always found them difficult to lock and painfull even if you aren't in danger. They seem more like an abuse technique than a finishing move (at least in my limited experience). Kneebars on the other had I love...such an easy thing when you stand up in an open guard.
Suck, Squeeze, Bang, Blow...
...that's what makes my thumper go