On the 17th Boedromion the potential initiates went to the sea to be purified. Originally they seem to have been purified individually by a priest, but as their numbers grew it was no longer possible to do so; bathing in the sea was a later alteration to the ritual, to accommodate larger numbers.
We know that the men and women bathed together, fully clothed from a fourth century BC incident.
A courtesan called Phryne, famed as the most beautiful woman in Greece, decided one year to remove her clothes. The Athenians were scandalised.
She was tried for impiety, but acquitted - on the basis that her great beauty could only have been a gift of Aphrodite.
Phryne went on to be the model for Praxiteles’ statue of the Cnidian Aphrodite, the first naked cult statue of the goddess, and the subject of countless tales of over-amorous men trying to commit unspeakable acts with her effigy. The cult of Aphrodite at Cnidus in Turkey was one of the rare Greek cults of Aphrodite as goddess of erotic love. These cults often had associated ritual prostitution, which so shocked the later Christians. In most temples Aphrodite was venerated as the goddess of marital love.
Drawing source: Cnidian coin depicting the Aphrodite.
After bathing, each initiate sacrificed a piglet on an altar, and some of the blood was sprinkled on the donors to further purify them. Female animals tended to be sacrificed to goddesses, so these were sows.
Animals were luxuries and expensive – most Greeks only ate meat at religious festivals - but a piglet had to be purchased for sacrifice, probably from the priests. We know of other sanctuaries, such as the Temple at Jerusalem, where animals could only be purchased from the priests to ensure they were of sufficiently high quality; this usually involved a mark-up on the cost of the animal, and provided an additional income for the sanctuary. The Eleusinian sows seem to have cost three drachmas a piece in the Classical period, and since slaves were initiated, were not beyond their means.
Small sculptures of piglets were dedicated to the goddess, so when they are found in an archaeological context usually indicate a shrine dedicated to Demeter.
The sanctuary itself needed state slaves to work in it, and seeing as only those who had been initiated could enter the sanctuary, they too naturally had to be initiated.
Some inscribed financial records from the sanctuary survive, therefore we know that it cost 30 drachmas for the initiation of two state slaves into the Lesser Mysteries at Agrae in 328/9 BC. These seem to have been slaves who worked within the sanctuary.
A few years later, the sanctuary needed some repairs, which none of the sanctuary’s slaves could undertake; as a result in 327/6 BC five slaves trained as builders were initiated into the Eleusinian Mysteries. They repaired the Telesterion, and in all probability went on to Elysium as a result of the mysterious knowledge they gained from the Mysteries.