Yes. The Zapper killed parasites well. There is a version of this - much more expensive - that is used by salons to regrow hair. Yes, it works.
Hmmmm..... interesting. Can you provide a link?
And there are those machine that speed up bone healing by sending electrical pulses, gizmos that pulse particular light wavelengths that will stimulate hair follicles, magnetic fields that can produce both bad and good effects.
All that being said, there will always be quacks selling worthless quack machines that claim to implement these technologies for $29.95, and if you order right now, you get a free set of Ginzu knives.