klugeryid:
Two responses to your recent comments.
1) I do not question the use of reward and punishment. However, it is beneficial within certain limits. There are age appropriate rewards. Think if you davened mincha today, and you were rewarded with a piece of candy. That would be rather absurd. It would not accomplish anything. perhaps, it might be accepted and an insult. This is not determined by any hard and fast rules, and one needs to have and exercise good judgment.
2) The quote from Rav Chaim shlit”a is identical to a statement by Rav Dessler, published in the Michtav Me’Eliyahu. I do not have it handy to give you the exact citation. My point is that discipline has its role, and the absence of it is exactly what Rav Chaim and Rav Dessler were suggesting. I do not disagree. Yet, if a child was behaving properly, and the father concocted something to smack him, there can be risk of driving the child away. Doing so without knowing your kid would be irresponsible. Your point fails to provide the basics of justification for the common practice within yeshivos to discipline as the main approach to chinuch. Clearly, חשוך שבטו never suggested to beat the daylights out the kid. Rather, it is note that the complete absence of discipline is counterproductive. There is a balance.
Back to the OP. It is not about intimidating, nor about instilling fear. Children (and adults) should have מורא רבך כמורא שמים. But that is not the fear of the potch. It is the awe. If we think that we can build positive awe on the negative of fear, we have a misguided confusion of the issues. The potch that teaches is the one that is limited, calculated, and within the context of a relationship between the rebbe/parent and the child in which the potch is educational, not punishing.