Alice B. Gomme, The Traditional Games of England, Scotland and Ireland," part 2, pp. 149-179, has seven tunes for British Isles versions of "Sally Water."

I.
Sally, Sally Water,
Sprinkle in the pan;
Rise, Sally, rise, Sally,
And choose a young man.
Choose (or bow) to the east,
Choose (or bow) to the west,
And choose (or bow to) the pretty girl (or young man)
That you love best.

Gomme provides 48! rhymes, and describes several forms of the game.

A version of the "sitting in the sand" (2nd line) given by Mark, is no. XXV and "sitting in the sander" is no, XXVI.
She doesn't "sit on a stone" in any of the given rhymes.
All of the rhymes are 'ring and sing,' there are no clapping forms of the game.

With regard to the water, she describes an Estonian wedding custom in which the bride, on the morning after the wedding, is taken to make offerings to the water spirit. They make an offering to the spirit, overturn a vessel of water in the house, and sprinkle their bridegroom with water.