Which one Nick 
I agree that they are necessary when facing express pace, but in a low level club environment where the rest of the technique is not tight, they cause more hassle than they're worth. If it takes 10,000 hours to be truly an expert at something, I reckon it would take at least 2,000 of those hours grooving your timing of the trigger movement. Something us mere mortals just do not have. If they're wrong then they cause balance, timing, confidence issues that just aren't therre if you stand still and straight. But if you think it helps then good on you, just think there are bigger parts of your game that will see you gain bigger rewards before messing around with a triggger!
Just my opinion, I'd never coach any-one out of one if it works but I would never ever ever coach one into a player!
I would also argue that trigger movements were the reason that Hughes was dropped from the Aussie team, and the reason that Cook becqame a walking wicket before Goochy got hold of him!