We do seem to understand some effects that involve a single molecule in the body, and the chips in this computer work using "impurities" and are actually many times times more pure than most things we deal with.
Most of us remember Avagadro's constant from school ?
Big number of molecules even in a small amount of stuff,and it is a number.
But homeopaths dilute all of it away.
The "50c" on the bottle means diluting part in 100 50 times.
That means if you took the entire universe, and just for fun a million parallel universes and diluted them this way the odds against there being even one molecule of the stuff there are millions to one against. It's probable that even the most successful rip off merchants have never ever shipped a single molecule of the "wise, empathetic, natural, empowered " substance.
Thus it's not how the BBC et al describe it as "like one grain of salt in the Atlantic", it's none. It's not "like" anything, because it ain't there.
To be fair some rip offs do it by 25C, which is merely like diluting an entire galaxy away.
Thus Homeopathy can best be summed up by the eminent forensic chemist, Dr. Clint Eastwood
"you've got to ask yourself one question: Do I feel lucky? Well, do ya, punk?"
Except of course the punk in question has odds of trillions to one against.
By an entertaining coincidence we ask questions on bullets in guns and Russian Roulette before we put people into banks.