I always thought choke collars were mean. I had a dog and tried to use one on her, she pulled and pulled on it and then she would gag and cough, so I got her a harness which she often managed to wriggle out of.
When we got a new dog, we learned how to use a choke collar and that there is a right and wrong way to put it on - it should pull towards the person, so if the dog is on your left, it should pull left. A firm but gentle tug to correct or direct the dog and a quick release are key to using a choke collar. This has been very effective with our dog and she now walks very nicely, heels and sits when directed. With consistent training they will sit and stay quite a long time.
I like the idea of having your hands free though! Where do you go to get something like that?
Actually we have two dogs now and never got around to getting another choke chain for this crazy ball of energy, he uses an old collar and one of those leashes you can make longer at will, someone gave it to us but we just use it because we had it already. He has gotten much better from walking with the other dog who was trained, but I think we would have to do more training before I could put them on my waist and not have him tangle me up and knock me over.