It is a natural diuretic that can cleanse the kidneys when consumed. This herb can promote increased urine output because of this, which allows for unwanted bacteria and toxins to be flushed out of the kidneys. It can also help to treat kidney stones and urinary tract infections as well. Try drinking parsley tea to cleanse the kidneys but adding roughly 1 tablespoon of crushed parsley to a cup of boiling water. Steep for 5 minutes, then strain. Consume the tea for about a week.