
You are right that there is no need to hit a dog. I trained my first Bearded Collie to a pretty good standard. She was very good with the leave command.
Until the day that she stole something! When I told my vet he laughed and told me it was my fault for not saying leave, and for expecting miracles with a high temptation.
I had taken the chicken out of the oven and left it on the top of the cooker. Then took the ironing upstairs.

I came back down to see my girl carrying the chicken to her bed. :-) I gave the leave command and she put the chicken on the floor and crept over to her bed. I have to be fair, when I picked the chicken up it didn't even have a wing broken off it. But I didn't really fancy it after it had been on the floor, so I shared it between the dogs the following day. I have to say that the chicken was warm and smelled delicious. She must have been salivating bless her. So an impressive leave (in my eyes.)
I expect my dogs recall to be spot on, and the leave command is my second "must have." I once spilt poison and my Toy Poodle raced up to it, but obeyed the leave command immediately. So I cannot emphasise enough what an important command this is. I know that lots of dog owners will have similar stories.