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, it will never have any cleansing effect upon the dark regions of your heart.
Physical water washing away external impurities has no effect on sin.
You can faithfully submit to any number of external, earthly religious traditions and still stand face to face with the issue of your evil heart. There is no ritual, routine or rote regimen that can cleanse a man’s heart of sin.
True impurity resides 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.