One place it doesn't work is razors. I've never been so happy with expensive razors and cartridges as I am with my simple, cheap handle and double-edged razors. But then, I do spend the few extra cents each for the good blades, so maybe it does work after all.
I use disposables, and have for decades. They are the three-blade ones.
There's a popular theory, called the "Sam Vimes Boots Theory," that applies: