If someone comes on my boat, I usually offer them tea or coffee, simply because I'm used to the nervous reaction when I offer them my own herbal teas. "Er.. no thanks, I'll just have ordinary tea/coffee!".
I don't blame people at all for this cos they might not like herbal tea or be worried about what's in it. But as I was making myself a herbal drink and got chatting to a dog-walker, I did offer some of my mugwort and red clover tea. The woman drank some and seemed very happy with it and we had an interesting chat about herbal remedies, traditional lore, etc. The next day, a man came past my boat and stopped for a talk - turned out he was the husband of the woman - and said " Oh yes, you're the woman serving witches brew". Ha! I had to laugh at that.
If you see my boat, I'll be happy to get the cauldron on for a cuppa ;-)