A few weeks ago the Antiochepedia site mentioned that an unspecified Arabic source 1 suggested that skin diseases could be cured by bathing in the town water supply. This rather horrible idea seemed unusual; but I wonder.
When I was in Leptis Magna, I saw the nymphaeum there. The temple was essentially a facade onto a massive concrete storage tank, which collected water from the rivers and stored it for use by the city. Temples of the nymphs are associated with springs, and sources of water in general, and thus with the urban water supply.
This leads me to wonder if this is what we are looking at here in Antioch as well; the miraculous supply of life-giving water being associated with the gods — the nymphs, here — and curative powers associated with the latter? If so, the procedure above would make more sense.
Note: 1. Antiochepedia doesn’t say what it is, other than ‘Guidi’, but a google search on Antioch and Guidi says that this seems to be a short early Islamic text, much of it fanciful. I. Guidi, ‘una descrizione araba di Antiocheia’, Rendiconti della R. Accademia dei Lincei, Cl. di scienze morali, storiche e filolgiche, ser. 5, vol 6, pp. 137-161 (1897). It’s only 24 pages, half of which at least is an Italian translation. I wish this existed in English. I wonder what it would cost to translate. Not a lot, I would guess.