This treatment methodology is very common on the Asian Peninsula, and for many T2s there it is often the only means of control available. I have not used it myself, but I have used several alternative treatments that are part of that methodology.
I have used cinnamon, Bitter Melon and Gymnema Sylvestre with some effect (similar to Metformin) but found that whilst these initially seemed to be promising, then after a while the effect wore off, and there was no change in BGL levels when I stopped treatments.
I too have found low carbing dieting has had a major benefit to my health, and surpasses anything I experienced with these supplements. Maybe the full ayurvedic treatment plan works better, but maybe it is also relying on placebo effect. As I say, I have not had a lasting benefit so far. My bgl levels for the last year have all been giving me pre-diabetic HbA1c levels, and that is good enough for me. It may be that my use of supplements did help to clear out some residual Insulin Resistance and did give me an advantage, but I could not prove it.
As has been said by others here, a low carb diet is both effective and Natural, so I recommend it to you as a feasibe way of controlling T2D.