While Quietex may help calm an over anxious horse, it's definitely not a tranquilizer. It's kind of like when you go to the dentist to get a cavity filled: first they dab you with that stuff that's supposed to stop you from feeling the needle (but it kind of doesn't - that's like the Quietex. Maybe it'll take the edge off, but maybe not). Then they numb you up with the novocain and you can't feel your face for 2 hours (that's like having a tranq).
But Sweetwater said it right. The more you work with his feet, the more he'll get used to it. When I first got my mare, you couldn't go near her feet without her kicking you. But I just kept picking them up, putting them down, picking them out like 5 times a day, putting hoof cream on the soles, tapping on her hoofwall. It was tough at first (I always wore a helmet!) but now she's a perfect angel about it. She picks her feet up without even having to ask. So stick with it! He may never love his pedicures, but he'll learn to tolerate it!