I'm not a parent myself, so I invite you to apply as much sodium chloride as you deem necessary. But what I seem to think are guiding principles is to apply as

I'm not a parent myself, so I invite you to apply as much sodium chloride as you deem necessary. But what I seem to think are guiding principles is to apply as little force as necessary, and only when the situation warrants it. And when it is applied, put forth a clear path to avoid the punishment in the future. I have zero recollection of this episode, but my parents tell me that when I was very young (3-5 years old, somewhere in that range) I used to sneak off an hide in malls when my parents went shopping with me, and no amount of time outs or revoked privileges could keep me from doing this (probably because the ability to punish kids through confinement or chores is limited when you're out in public with them). This extended to the point that stores had to be shut down and staff called to help search for me. My parents tell me that my dad took me to the car, explained why this behavior was unsafe and unacceptable, and that they had exhausted other disincentives before resorting to physical punishment before proceeding to spank. Supposedly when I would start to wander off my parents reminded me of the physical punishment, and clearly explained that this would be the consequence if I repeated that behavior. Society works similarly. When people do bad things that are not exceedingly harmful we fine them or revoke privileges. Drunk driving is almost certainly more serious than kids sneaking off in malls. And we rarely apply force in that situation, preferring to fine people and revoke their driving privileges. Physical punishment in the form of imprisonment is reserved for things that are exceedingly harmful and dangerous. And when physical punishment is issue for things that aren't truly dangerous, like drugs, it's recognized as an injustice - at least by a significant chunk of society.