Bottom or hand only. Face is out of the question. And coming from a parent only.
For those of you too young to remeber the 70s, petch was the norm in Brooklyn. Real bad deeds got the belt, the ruler or the tablespoon. Really REALLY bad deeds got the whack on the finger tips (palm up, fingers closed into a pyramid)
This was from parents and school alike. But today? School staff has no right to do any of these things. Even parents need to rethink how and when.
Oh, and now that I think of it, bad words got special treatment. Depending on the severity, it was either liquid soap in the mouth or black pepper on the tounge. As you can guess, I was a real chevrah-mahn 😉