Well, these days, when a homeopathic remedy has a “very small” amount of herbal ingredient, it means “once upon a time it touched some water, and then we diluted that water with gallons and gallons more water.”
“Water memory” is from “the doctrine of contagion,” which was the ancient idea that anything that had ever touched anything else would always be connected with it afterward. It was often used for spells (which people thought were also scientific) because it taught that doing something to one thing would do something to the other thing it had previously touched, even if they were separated and would never actually touch ever again. It used to be a “natural philosophy” idea, back in the days of the Greeks and Romans, and it stuck around in medicine for a long time because people didn’t know better. But now it’s only believed by Wiccans and homeopathy. Continuing to believe in it is believing in magic.
Popularity doesn’t make a thing true. “The doctrine of humors” is still a big part of Indian “Vedic medicine” and Muslim “Greek medicine,” even though medical science in the West stopped blaming depression (“melancholy”) on black bile hundreds of years ago. There are some things that they’re good at (wellness treatments, in many cases) but it’s not the type of medicine I’d want to trust my life to. Medieval-style humors medicine is a pinch of good stuff and a bushel of scary bad stuff.
In the olden days, US homeopaths actually did treat people with herbal remedies (and they were often effective and knowledgeable doctors), but now it’s usually all water, all over the world. Having brandy in the water seems like a superior way to go.
Of course,
if you’re not driving and you really want an herbal alcoholic remedy, you should go with Chartreuse (the Carthusian monks’ secret blend of herbs and spices!), Jaegermeister (yup, it tastes yucky because it’s full of herbal forest goodness - it was originally sold as medicine for hunters), or pretty much any liqueur or liquor that was originally designed to be a “digestive.”