The reason why I'm asking is that I'm taking her to a clinic at the end of the week and had been considering giving her quietex before the 3 hour trailer ride. The drive there is really curvy in some places, and she hasn't been trailered in a long time. I've used it before and never noticed a considerable amount of difference.
I used the tube paste once to trailer my horse who can get nervous when he travels. It seemed to work, but it took a while to take effect. I wouldn't ever use it daily, just for trailering or other stressful infrequent events.