Also it's the theory that like cures like, so you take a homeopathic dilution of ebola to cure bola, or if your having a asthma attack you take a homeopathic dilution of cyanide, and otehr stupid things.
It's not quite that direct; the homeopathic 'Principle of Similars' suggests that
anything that causes similar symptoms can potentially be used to cure the malady when taken in very low doses (e.g. raw onion makes your eyes & nose water, snuff makes your eyes & nose water, and makes you sneeze, so both might be potential remedies for a cold); selection of the most effective remedy from several substances that produce the same symptoms is called 'proving', and involves giving a dozen or so people homeopathic doses (i.e. nothing) of each remedy and having them record their thoughts, feelings, dreams and habits, which are then analyzed to find the most efficacious remedy. All subjective, no controls.
Incidentally, the originator of homeopathy, Samuel Hahnemann, thought that even extreme dilutions would still leave some of the 'active' ingredient in doses, and that the more extreme the dilution the more effective the dose. Subsequently, Avagadro's work on molecular theory proved that this was incorrect, and that doses of all but the very lowest dilutions would contain none of the remedy at all. It was then that explanations such as 'water memory', and so-on, were devised to preserve lucrative businesses.
Every idea in homeopathy, from the Principle of Similars, through potentization (dilution & succussion), proving, etc., is complete nonsense scientifically, and each idea is an entirely independent piece of nonsense; it's a remarkable achievement and a testament to the combined effects of the profit motive, gullibility, and the placebo effect, that it continues today.
One positive aspect of traditional homeopathy is the detailed consultation, which is known to enhance the placebo effect; the other benefit, particularly in the days when certified medicine involved large quantities of toxic substances and blood-letting, was that it is quite harmless, even when the remedy involved is extremely toxic.
See
Homeopathy.