Every dog trainer has their own preference in what they use for training.
I like to use collars instead of the harness because you have more control and when they feel the pull against their chest then it gives them more dominance and they think they’re all big and bad.
Yes of course there’s the no pull harness and other tools but I honestly have not used them. Think of sled dogs, as soon as they feel the pull against their chest then they feel the dominance and they want to start pulling so no matter what the size of the breed is that is what they feel.
The dogs do not care if you pull their body to try and correct them but it is more uncomfortable for them to feel the pull around their neck. As long as you get a nilon or leather collar, it does not harm the trachea. If the dog is a medium to large dog, please get a thick collar because it is uncomfortable for the dog when the collar is to thin. It can loosen up easier and fall to the bottom of the throat, which will make them cough and then scare you because you think they are choking.
When the leash is on the collar and you give the dog a leash correction, you do not have to pull back with all your strength. Just a little pop back on the leash toward the tail is good enough.