Looking for the symbolism of the Elysian Fields, dark and light, bathing (water)

Elysian Fields represented the place in Greek mythology where heroes went after death. It was a place of relative joy - at least the heroes were not as likely to fade away as they would have in Hades. Dark and light are nearly always contrasted to show evil and good; "bad" things happen in the dark, yet the light also shows the truth which is why Blanche tries to avoid it. Bathing, in fact, should be symbolic of cleansing, but sometimes things happen in the bath that are not as cleansing as one might think; sometimes cleansing cannot be achieved.