Mussels and clams are best enjoyed when they are thoroughly cleaned and shucked immediately. This is a tough task, in order to get all of the grit out of mussel shells. First, you must clean the outside of the shells well with a scrub brush. But if you want to get the grit out of the inside of the mussel, you need to do some simple steps with a household product: cornmeal.
FIll a shallow bowl halfway up with water. Add 1/4 cup of salt to every 2 cups of water.
Place the mussels in the shallow bowl, large enough so they can be evenly distributed without stacking on top of each other.
Sprinkle a generous amount of cornmeal over all of the mussels and water. Cover with foil.
Put in to the refrigerator and leave the pan in there overnight. In the morning, you will see lots of waste and grit in the water, which is a good sign.
Dispose of the water, and hand rinse each mussel with clean water.