Check the walnuts to make sure the hulls have all been removed. If not, hull them yourself, wearing rubber gloves and using your fingers, a pocket knife or a hammer to remove the exterior hulls from around the shells.
Wash the shelled nuts to remove any remaining hull pieces. Fill a bowl, bucket or tub (depending on the number of nuts you have to wash) with warm water and dump the nuts in.
Spread the walnuts in a thin layer (no more than three nuts deep) over a flat surface, such as a wire screen. Place the surface in a cool and well-ventilated area in which they will not get wet, such as a garage or shed.
Stir the walnuts every day with a wooden spoon or other kitchen instrument to change the exposure each nut receives, which will facilitate drying time.
Allow the walnuts at least a week to completely dry. This process can take longer depending on temperature and humidity. You will know the nuts are dry when the kernels and shells become brittle instead of rubbery.