I, too, have known showers like the Power Shower, and they are fearsome creatures indeed. It desires not libation, but vengeance upon others. Therefore, the libation is best used on yourself rather than on the beast, whereas the Vengeance is best exacted upon other unsuspecting victims. Best served cold.
As for your own ablutions, Ned, I suggest a large pail and a ladle. (Or, as we call it in Tagalog, balde at tabo.)