Homeopathy is based on the principle of diluting an herb with water until none of the substance remains, then selling the water for $10—or $100. Inert powders are also used as the dilutant, with the same results.
Take, for example, the "HomeoFamily Kit", which is a big drawer full of tubes. Most of the ingredients listed are "30C", which, in homeopathy jargon, means that an extract of that ingredient was diluted 100 times, thirty times in succession. This means that it's so dilute there would be perhaps one molecule of the active ingredient remaining in a sphere of "medicine" 131 light years in diameter.