Hickock45 does some great videos on YouTube.
Luckily, my fingers are short enough that it's not physically possible for my fingers to ride too close to the cylinder as he is trying to demonstration. Many of my students, however, are able to reach that part of the gun, and I have to school them before-hand on the 'right' and 'wrong' way to hold the gun.
It's all about safety.
What is the point of rules that are not enforced?