Newest craze to re-grow thinning hair, is it for real?

Hi there, My mom just returned from a vacation in India and everyone there is into this circulation exercise where you rub your nails together as many times as you can daily and over a 5-6 week period they claim that after doing this their hair is growing back. She suggested I try it since there is no harm, cost, etc. I haven't started but do you think there is any validity to this?