It does NOT take a spank of hard strength to get a reaction, as the pendulum effect of the wrist simply moving back and forth, sends the tawse way backwards, and then rushes it forward to the waiting target.
However, if you want to give a even fiercer effective spanking while the spanker is standing, then the long tawse is exactly the implement to use. The arc must be frightfully large, momentum must increase automatically very quickly, and the flexibility of the leather makes it wrap to the skin covering more than any rigid implement. the point of contact is the entire two leather strips, which separate on the way to landing on your bottom, thus no little cushion of air is trapped to moderate the spank.
a few smiles for today