Hydranos
The hydranos was an official in charge of purifying the faithful. In the early years, when the number of believers was relatively small, the Hydranos could supervise and conduct the purification process by sprinkling water on the mystai. However, when the number of believers increased, it would be practically difficult or impossible to continue with individual purification. Therefore, mass cleansing at sea was introduced and took place on the 16th of Boedromion. During the elasis, which took place that day, the mystai travelled to Faliron or Piraeus and cleansed themselves in seawater.
Lekythos. Persephone With Torch And Phiale Pouring Libation, Demeter With Staff And Sheaves Of Corn, 475-425 BCE, vessel, National Archaeological Museum, © Hellenic Ministry of Culture and Sports/ Hellenic …
