Technically that is still just running it sterile. You don't need to add anything to run sterile, you just need to keep your reservoir temps at a level where you don't get pathogens. Since not everybody has an environment where they can keep temps in the goldilocks zone, understanding ways to keep your roots healthy is very important. How is that a fad?
No offense taken at all. I stay far away bleach in my res personally. I've had to use great white in the past when my temps got out of control and it helped, but temperature control is where it is at.