Alas, many herbs that have some decent symptom relieving effect, don't taste very well. Chinese medicine is notorious for terrible tasting decoctions.
It's not too surprising that some herbs do well as pain relievers, a lot of them seem to thin blood. One reason surgeons want you not to take herbs prior to surgery and coumoudin has so many interactions.
The mechanism of action of herbs is not well understood, which isn't that surprising as until fairly recently (1971) the mechanism of action of aspirin wasn't understood.
How Aspirin Works