Training the Headbutt with Aliveness
I've been browsing through old Bullshido threads about headbutting. While I found some good pieces of advice on the mechanics of how to deliver a headbutt (both standing and GNP headbutts), there wasn't too much on how to train in delivering them.
Since my general attitude towards sparring is the more variables in play, the more fun, I'd like to start discussion on how the headbutt can be safely and effectively trained with aliveness. It seems like a potentially useful weapon to have in one's toolbox, and I don't want to let to fall into the BS "too deadly for sparring" rhetoric.
Does anyone here know how headbutts are trained in Daido Juku or Bando? I've seen some pretty remarkable use of the headbutt in Daido Juku, and I would be surprised if those guys were just pulling them out of their hat on in the middle of the fight without ever practicing throwing them on partners in the dojo. For that matter, what about old-school Vale Tudo fighters from the days when headbutts were legal? Did these guys train in them as a part of their sparring?