Vibrational medicine, also known as vibrational remedies or energy remedies, is a particularly asinine part of the lunatic fringe of homeopathy, apparently the bastard child of homeopathy and radionics. According to proponents, the "energetic imprint" of the mother tincture is transferred by some kind of magic to the remedy. Naturally this is not energy as the real world understands it, but woo energy, the type which has no objective existence.
Typically, the HCG diet scammers are promoting this as being "compliant with FDA regulations" - this is a response to the fact that homeopathic HCG is illegal (because it's not in the Materia Medica, not because it's fraudulent - that's America for you). Yes, it's legal, but only because it's even more fraudulent than homeopathic HCG.