If I have, say, a saucepan on the stove over medium heat for ten or 15 minutes, the handle gets too hot to hold without a mitt. But just run it under cold water for a few seconds, and it cools down. Totally. It’s a solid piece of metal with sort of bumpy surface texture. Could those bumps dissipate heat so much more quickly? I’d expect a hunk of metal to stay hot for quite a while. I am trying to determine if it’s a matter of my perception and expectations, or of an actual “advance” in the design of cookware.
Water is a really really good coolant. It’s got a higher heat capacity than many metals, and pretty high conductivity as well. Plus with running water you have all the advantages of convective heat transfer: the water that is slightly warmed by the metal is nearly instantly replaced by cooler water.
About your specific pot, anything that increases the surface area of the handle will increase the rate of heat transfer, but the effect is probably trivial compared to the overall effectiveness of cool running water. Perhaps a handle without the bumps would take an extra second or two to cool.