What does Dong Gong mean by saying that the water on election day is clean?

Only when Bingzi is clear is the water.

Stator day: Bingzi water is clean, and when it meets the prosperous land, Huangluo rosewood is full of stars. Suitable for building, burying, getting married, starting business, traveling, entering houses, starting work and breaking ground. Gengzi, Wuzi has been. Nono-Wood is an untimely bottle of precious water, a tree with fallen leaves and roots. The gold that Jia Zi died by herself is worth autumn gold and is not suitable for use.

Don't pay too much attention to this superstitious statement!