What assumptions are you making about my, or anyone elses, education?
In my experience, despite having provided ample space for the inhibitor by draining a quantity of water from the system, it will not flow from the Tee pipe into the radiator that I use as the insertion point for inhibitor. Rather it flows out. It doesn't matter if I use the Tee at the other end of said rad so it's not the angle of the rad that is causing problems.
Richard