I have both encountered personally and read of the use of another method, though as far as I know it was applied only to girls. That is not to say that girls were more likely to pull their hands away, but simply that I have only seen and read of it with girls.
In the event that a pupil kept withdrawing her hands, she was sometimes required to sit, usually on a desk, or on a chair on the teacher’s platform, to secure a suitable height. She then had to hold out her hand or hands above her legs, sometimes with her dress or skirt pushed back to make the prospect more intimidating. If she then withdrew her hand the strap or tawse would rather painfully strike the front of the thighs.
I saw this method used in the final year of Junior school when one of my classmates kept pulling her hand away from punishment with a ruler. In that case she was told to hold her hands close to her legs. With a tawse or strap, I presume the hand would be extended at just below shoulder height as normal, the length being sufficient to carry down to the legs if the hands were withdraw