In my experience, and based on talking to others who I know to have been real teachers, some of whom still are, it would have been a very unusual school in the twentieth century where bare bottom caning was normal and routine. I cannot say that there were no such schools, but it was not a normal practice. On the other hand, schools where it occasionally happened, in very serious cases do not appear to have been all that unusual.
Few people would have said anything against a schoolmaster who occasionally administered such punishment, but one who did it more than occasionally would have, at the least, been viewed as having somewhat suspicious motives.