The Apollonios (second century BCE) mentioned in the previous post cites the work of an “historian” who reports the following “marvel” (avert your eyes, if you prefer, since it’s a little racy):

Phylarchos says in the eighth book of his historical treatise that in the Arabian Gulf there is a spring of water and if a man rubs his feet with it his genitals immediately become extremely erect. Some persons’ genitals do not contract again at all, whereas others’ do return to normal size but only after great suffering and treatment (Hansen, p. 6).

History can get a little “racy” at times.