If you have never had one, I can attest that the effect of the water substantially increases the sting. I have heard arguments about the physics of it. I don’t know about that, but on the practical side – it works.
I have given more of them than I have gotten and each of the lasses was impressed with the effect – as in GD it, that stings like a swarm of hornets.
The first swat of the paddle displaces most of the water, so by the third swat, the effect is greatly diminished. I think the best way to do it is with a third person who uses a water mister to replace the water after each swat. And everyone is going to get wet.