The Junior Nylon can be cleaned with a damp cloth or with water and a mild soap. This will eliminate many stains. Stubborn stains can be removed with a mild, patio furniture cleaner (without bleach). Most home improvement stores sell it.
The cover for the Junior Stonewashed can be washed inside out in the washing machine, at thirty degrees Celsius (about 80 ºF). Use a detergent without bleach!