Honestly, I feel that the mac method is only going to work on Alden shoes. Alden puts this kind of high shine dye job on their shell to make it their own. But I mean the "Mac" method is just really wiping your shoes, brushing them, and every now and again using wax polish. It is nothing legendary. Then again he says to wipe them down with a damp cloth. Honestly, this is where I feel it would only work with Aldens. Every bit of shell I have encountered doesn't respond well to water unless there is a very thick wax finish on it. It swells up and leaves marks and such. I think the Alden finish repels moisture to a certain extent were wiping it with a damp cloth literally is just getting dirt off. Another thing about Mac is he seemingly only wears his shoes a couple of times and then flips them on his site. I would be surprised if his alleged "wax every 15 wears" ever gets reached. Also, as noted he takes his pictures outside in natural light. This helps for the camera.
Ultimately, you can treat shell like calf. Also, Venetian shoe cream used over a wax polish in sparing amounts, swirling it around slowly has a very bulling quality. That is what I use to maintain the bulling on my shell shoes and even toe and heel counters of my calf shoes.
I am too lazy to do heels, you have more patience than I do. Yea, I am currently on a shoe cream + Reno some time regime for my CJ and Rider shell, not mirror shine (would need wax for that), but enough to my eyes
I know, I spend less time on the heels, but it sucks for sure. I generally do it once and just try to milk it out and maintain it for as long as possible, which is generally getting caught in a rain storm or something then having to clean, condition and so on.
Also, the grain on shell is very inconsistent. Some parts are like plastic and have almost no pores and some parts are very, very rough so this makes the shine take and hold differently in different areas.