There is some support for the latter view, because the nearest formal parallel for such bowls from antique contexts is in depictions of the Oracular Cortina, a three-hooked bowl suspended within a tripod, over which the priestess sat when pronouncing oracles. Certainly if water were contained in the bowls it is more likely to have been for ritual or liturgical purposes than for general consumption owing to the limited capacity.
The argument in favor of the latter view is supported by the fact that similar bowls, found in ancient contexts, are depicted as being used for oracles. The priestess would sit over a three-hooked bowl suspended on a tripod when delivering pronouncements. If water were contained within these bowls, it was more likely to be used for ritual or liturgical purposes rather than everyday consumption due to their limited capacity.