I did this for a while after seeing that video, but after some of my shorts ended up tightening into a knot that I couldn't get loose easily, I gave up on it.

I instead just use the "Ian Knot" that I use to tie my shoes. It's very quick, I already use it all the time anyhow, and it rarely goes wrong. (Sometimes, I think I end up with an end through a loop accidentally, and have to fix it.)

Learning this extra knot didn't really help much, and it definitely went wrong more than I liked.

Ian Knots is a rabbit hole of great practical knots and shoe lacing styles.

You just pull the loose string end to relieve the knot? The loop just pulls out.