The Grit Guard is a raised grid surface that sits in the bottom of the included 5 gallon bucket. Fill the bucket with your favorite shampoo and water and place the Grit Guard in the bottom. Load your mitt with soapy water and wash as usual. When you dunk the mitt back in the bucket, drag it across the grid to remove dirt that has accumulated in the nap. The dirt will fall between the slats and settle in the bottom of the bucket. Even though you agitate the top water every time you reload the mitt with soap, the Grit Guard stabilizes the water in the bottom of the bucket so the dirt does not rise. Simply stated, your wash water stays clean so your mitt stays clean. Clean mitts make no swirls!