That You Tube video is slow loading...

"Ball and dummy" aka "skip loading" is simply loading three live rounds into a revolver cylinder--two rounds into adjacent chambers, "skip" one chamber, and plug the third round in. Then spin the cylinder without looking at it, and close it. Each time you squeeze the trigger you have exactly a 50% chance of getting a "click" (or a bang).

The point is to develop trigger control and follow-through. The noise and fiction of the weapon firing covers what you did, or think you did at the moment of firing. Hence "The sights were right on when I squeezed (yanked?) the shot off".

It's the empty chambers that tell the story. If you do it right, when the hammer falls, NOTHING HAPPENS. The sights stay aligned, the muzzle does not dive "low and left", you do not close your eyes and grimace. if your follow through was very, very good, it was defitely a good shot; congratulate yourself. Then do it again. Nobody else may know what you're doing or how well you did it, but YOU DO.

Not only does it stretch the ammo supply, but the instructor can wander off for a beverage while you stand there and beat yourself up. Everybody wins. It really works.

Variations are obvious. Doing this with lightweight snubs (just adjust the rounds in the 5 shooters) cushions impact; load 1/4 or 1/6; use .22LR; for semi autos throw some dummy rounds in the mix.

It's all very simple--just maintain sight alignment through the shot, cause the hammer to fall without disturbing same, and lots of follow through.

It's just not easy to do each and every time! (and I don't, either.)