I can’t imagine piercing the end of an egg without is breaking in my hand but he makes it sound so good I have to try it anyway.
Hold the egg in your left hand, and pierce the egg with thumb tack held in your right hand. You can turn it too so it kind of screws in. Don’t worry, the egg won’t break.
I use a push-tack (from the cork board). Make sure you pierce the round end.
This works because there is an air sack in that end that is separated from the egg by a membrane. As the egg cooks, it will expand a little as does the air in the sack. Without the hole, the egg is more apt to break.
I pierce eggs in this manner all the time in order to blow out the insides to use them for origami papered Easter eggs (though nowadays I also use ceramic eggs). It works fine. Once in a very great while you break one, but almost never. I use a bulletin board pin with a long sticker, like the plastic ones that come in colors or clear plastic. It works.