and there are hundreds of idioms..
wet your whistle is the first that comes to mind..

and while water is free, (so we don't water people) we do offer as mav says, refreshment, cuppa's, coffee, a nip, a cold one..
and we speak of it.. that way.. we settle things over a cup of coffee, (tea), we sat down and had a cold one..

since it rare that humans (in this day and age drink without a cup or glass, or for that matter just drink water.... we don't water--(but for our health, we might take the waters at Bath!)



my other obsession