I found it interesting (and you might!) that on the very week when I have been discussing the limits of clicker training with people who advocate using all the time (or as much as possible) I meet two of the strongest horses I have met. Ben Hart has written an eloquent article on the use of pressure halters in training and he certainly feels that there is no place for them. All of this is helping me to clarify (but hopefully not freeze) the limits of my horsemanship. I will continue to use pressure halters in those circumstances where I feel it is necessary for the safety of the horse, the safety of the people around me or the safety of me! I have always tended to use them in a flat linear way rather than in a jerky motion.I cringe when I hear people say that they yanked on the Dually. There's no need. I have always used body language first (mental pressure) and physical pressure second. The scientific definitions of what constitutes negative reinforcement and punishment, don't measure it in terms of the discomfort it causes. Both negative reinforcement and punishment can be applied without using any physical pressure at all. Alternatively, either could be applied with the use of great physical force.
There have to be situations in which a trainer will walk away and I have always walked away from situations in which I feel compromised - for example, I won't work with horses where I know that they will continue to be hit after I have gone, I won't load horses on a hard surface and I won't work in situations where there is a real risk that the horse or myself might get hurt. However, I won't leave owners in the lurch with horses that have learned to walk all over them and where all that is needed area few well defined rules, consistently applied in order to get them back on track. These days, I am happy to incorporate clicker training into my repertoire if I feel that it will it will be a positive benefit for the horse and their owner.
I am really enjoying testing my own boundaries but sometimes it does give me a headache.