It's very true that the feet represent "microsystems" of the entire body -- as does every sub-region of the body. That means that each hand represents the entire body, as does each ear, the scalp, etc. I've heard of eye acupuncture (around the eyes, not in the eyeball!), nose acupuncture, wrist acupuncture, and even tongue acupuncture. I had an acupuncture teacher who told us that the entire body is represented in each of the body's 100 trillion cells, and that if you had a small enough needle, you could limit your acupuncture to just one cell and do everything you could do with whole-body acupuncture! So it's true that there are points on the feet that represent each organ, and those could be stimulated in the manner suggested.
That said, I would be surprised if any amount of stimulating the adrenals, pituitary, etc. will make an adult grow further. I would only buy this device if they offer a money-back guarantee.