[Itspuppyluv]

I'll have a go at it.
It has to do with the bond between you and the dog. A gentle spank doesn't seem like much but there is either pain or fear involved or it would not work. You are teaching your dog to fear you. I'm sure there are a lot of people that think that is fine as long as he doesn't pee inside my house but do you really want your dog to be afraid of you? When it is completely unnecessary?
You might not see it and your dog cannot tell you but put yourself in his place for a moment. What if someone took a newspaper and smacked you on the nose when they wanted to get you to do something?

It took me longer to train my dog but he worships me and I am being completely honest when I tell you I could probably teach him to do anything I wanted at this point. He will do anything to please me.

Housebreaking takes patience, consistency and vigilance. ESPECIALLY with yorkies. Your dog is not failing you, you are failing him.

Hitting him you are getting the fast fix but it comes with a price.