Phil McShane said he was trying out a new approach. In the past, he had tried to present the whole of Lonergan's economics, and he had failed to make any impression. Now he was trying to go step by step. The "Grade XII Class" was one such effort. The 8 articles in Divyadaan: Journal of Philosophy and Education was another effort in the same line, introducing the notions of basic and surplus circuits, promising, credit, money, and the goal of the economy with the help of examples of simple businesses.
My impression is that this new strategy is helpful. Though it is quite impossible to assume that I have really understood, still, it is a good start. I found that, against the background of my reading of the articles in Divyadaan, other reading began opening up: Michael Shute's Lonergan's Discovery of the Science of Economics; McShane's own Sane Economics and Fusionism; Anderson and McShane's Beyond Establishment Economics: No Thank You, Mankiw.
So "economics slowly by slowly" seems to be working... Though I think it is possible sometimes to go too slowly; then a little speed might help. A variation of approaches, then. McShane himself admits the need to break up elementary presentation with the long term view.