Urethane or Polyurethane foam is commonly used for home insulation, mattress pads, and mattress, couch or chair filling. It is more commonly referred to as "memory foam," a name it gets because of its ability to retain "memory" and conform to a person's body. Cleaning this type of material requires a bit of extra patience and care compared to other fabrics, but it is still possible to do in the comfort of your home.
Lay your urethane in the bathtub or on a surface that can get wet. If the urethane foam is a part of your couch or chair cushion, unzip the cushion and remove the urethane material.
Fill a spray bottle with one part detergent and two parts warm water. Shake the spray bottle to mix the solution.
Spray the entire surface of the urethane foam. Flip it over and repeat on the other side. Once you've finished spraying both sides, let the detergent solution set for 20 to 30 minutes.
Wipe the detergent solution off with a damp washcloth. Do not spray with water.
Allow the material to air dry, but avoid direct sunlight. Depending on how wet your urethane foam is, it may take 24 hours to several days to completely dry.