I haven't heard of vinegar/honey but around me they use straight buttermilk ,no proportions,but next..or I should say this year, I might try your vinegar/honey and you might try mine and we could compare..good luck ........ Tom

I saved a magazine article that instructs one to coat the item with a thin layer of plain yogurt, then to rub the coated surface with a piece of the moss. -- Same concept as the buttermilk, I suppose, but the yogurt might adhere a bit more readily. I've not yet attempted this, but I intend to try it on a couple of old concrete pots.

The honey/vinegar option is interesting . . . I'm going to check around to see if I can find out more abt it.