Never, I never use that system. I think the reason people have trouble reading bass clef--and almost everyone does--is that they see it as a separate system from the treble, and it becomes two things to learn instead of one. Once the student can name all the notes on the keyboard, I teach the whole staff as one "canvas" for drawing notes. I draw middle c on it, then the next two c's up and down, and then the leger line c's above and below. Then I turn it sideways to show how those notes look like a mirror of one another, and that makes them easy to remember. Right away, they have several notes that really jump off the page for them. And since their written pieces at the beginning tend to be based on those c's, they're immediately useful. Next, I have them draw and play 5-note scales on each c, then show thirds and fifths (maybe not using names, but describing and looking at the spacing, which they can see right away). It only takes a few minutes to go through all that, then they can look at any beginner's book and start playing. This only works for me when I start a student from scratch and their parents don't "help" too much at home. Once someone learns Every Good etc, I have a much harder time helping them to read well.