Headstart:
You mentioned that it was "a hand-held device" that was "originally invented to reduce stress" but had an unexpected side of effect of growing hair.
Now I remember...isn't this the 'Happy Wanker 2000'. I also heard it grows tons of hair but, unfortunately, it's only on the palm of your hands. Caution...too much use will give you "Popeye forearms" and may also cause blindness.