Some people in the US live in apartments. Get up - leave for work at 7 - dog in crate - get home at 5 let the dog out - go to bed at 10 - put the dog in. it's horrible IMO.
Also choker chains should be worn up around the dogs ears - that is where they are intended to be used. A short sharp effective jerk using them there can be useful - however, there are better things to use that are less dangerous and work to build up a rapport between dog and owner - as opposed to breeding obedience for the sake of obedience.
I did a trial once - and only once. I had cappy on a flat collar and people were seriously asking me - how do you control him on a flat collar? If you need a collar to control a dog, you need to think about where your training is at.