Fortune telling drinking water

Can I drink the burnt ash given by the Taoist priest with water?

This should be the way I heard that the fortune teller Daxian treated the disease. I have seen daxian treat people in this way. The "patient" had no special reaction after drinking Daxian's gray water, which was non-toxic and had no side effects, but the taste was a little worse. As for the effect, "God" knows!