Dust your Hampton Bay chairs periodically with a duster, or wipe them with a rag. This removes dust and dirt buildup. Be sure to dust the chairs prior to washing them.
Prepare a cleaning solution of 1 tablespoon liquid dish soap in 1 gallon of hot water. Alternatively, prepare a 10-percent bleach solution, mixing chlorine bleach with hot water.
Wash the chairs with the soap solution or the bleach solution. Rinse the rag as needed, and wash all crevices in the vinyl.
Rinse the patio chairs with a hose within 15 minutes of washing them. On a hot day, rinse them sooner, before the soap solution dries.
Let the chairs air-dry in the sun.