Whenever I take one of my cats to the vet, I spray Feliway on the towel inside the carrier. It calms them down.

The "medicinal" smell the cats can sense, is scary to a cat. Keeping them separate for the rest of the day is a great idea. You can also take a dryer sheet and rub Smokey down with it. It'll take any static cling out of him and also leave him fresh smelling.

Good luck. Let us know how you make out.