I have a number of locking cord ends (outlets) for extension cords that do use the holes to retain the male plug via ball detents. They require you to push a button to release the plug.

https://www.homedepot.com/p/15-Amp-Stay-Plugged-Cord-Replace...

I've never seen anything else similar.

I'm curious on the design of "hospital grade" plugs as that wasn't in his survey and I know that they are designed for higher retention force than commercial or residential applications.