One country in which it was once as common as here-France. As they have a verb for it(Fesser), I wonder if a word search will find similar verbs in other languages?
That might pin down which other non-English speaking countries have a word for it & therefore probably practised it. We will also need to consult the dictionary to find the derivation of spank itself-wonder if it is from Old English, French or Norse?
Also, were there other non-English speaking countries that abolished CP in schools as late as the UK(1987 state schools)? That would be a strong indicator spanking was still fairly common in homes in those countries.
I’m sure my fellow Forumites will be able to help you identify others apart from France.