For the people of Mesopotamia, the month of August-September is for washing the statues of the Goddesses. In mid-month, the Ezem-Inanna-Ka occurs. This is the festival to prepare Inanna for her descent into the Underworld. People wash and consecrate her statues (usually in a river). For Sumer, the month is called “Kin-Inanna” (the work of Inanna), for Babylon, “Ululu” (to purify).
The washing and the consecrating the statues of the Gods is a venerable Polytheist tradition. Keeping holy items neat and clean is a duty of piety. Sacred things are always kept pure. Therefore, cleaning statues, altars, and temples are encouraged at this time.