If you buy a bit does it mean you have to hang it on him for the rest of his life?
Using a twisted wire properly for a schooling session, isnt going to kill a horse. There is nothing wrong with using that bit, again, if you know how to use it, to achieve a different feel and going back to your smooth snaffle.
If you plan to step up to that bit and consistantly use it you risk getting caught in the "need a bigger bit to control my horse" mode.
But, if your horse is hard in the face you need to rethink why.
I DON'T LEAD 'EM AND FEED 'EM, I RIDE 'EM AND SLIDE 'EM.