Sluice is a verb that means to cleanse or rinse with water. 

Dating back from the 17th century, our word of the day was first used as a noun to describe a gate used to hold back water. In time it became a verb to describe the act of watering something. Here’s an example:

I really need to sluice that porch. All that mildew and dirt need to be rinsed off before our party guests arrive and are too disgusted to enter our home.