Nothing that goes into a person from outside can defile him, but the things that come out of a person are what defile him.
You can wash your hands repeatedly and it will never have any cleansing effect upon the dark regions of your heart.
Physical water washing away the external impurities has no effect on spiritual sin.
True impurity proceeds from within the human heart. It must be cleansed by the blood of Jesus from the inside out. There is no other solution for the darkness that indwells us.