A good kennel is set up so that you open the door to where you want the dog to go and you open the door to where the dog is and it forms a hall of sorts so that the dog has no choice. I agree that a choke is best in any situation involving a leash.
Ah. But, you're also talking about a "kennel". Doesn't account for the vets, who often simply walk the dogs outside the office for potties. Indeed, I would like if I knew my vet had max control over my dog when she needs to stay overnight.