What I liked about this technique was the change of position, which provides less sun exposure to different areas of the body and therefore less sun exposure time to the skin.
There are other points I am skeptical about. There is no recommendation for skin phototype, as it is well known that white-skinned people hardly ever tan; they get sunburned. There is no individual approach to the patient's region of residence. People who live in the south are less adapted to sun exposure than those who live in southern regions.
However, I would not totally deny this approach. After all, people who like a systematic approach will not be harmed by this method. As a doctor, I do not recommend using this extreme method for blondes or people with light hair.