Sweep dirt and debris off of the deck. Wash the deck with a power washer to remove deeply embedded dirt. When using a power washer, set the spray nozzle to a medium width spray pattern. A narrow width spray pattern from a power washer will carve grooves into the decking. Spray in the direction of the wood grain.
Allow the decking boards to dry overnight before applying the stain stripper.
Fill a pump up sprayer with deck stain stripper. Saturate the deck with the stripper and allow the stripper to set for the time that is recommended by the manufacturer.
Scrub the decking boards with a long-handled scrub brush to help loosen and remove deeply ingrained stains.
Rinse the old stain off of the decking boards with the power washer using the same technique and spray pattern as in Step 1.
Mix approximately 1 gallon of deck wood brightener with 3 gallons of water. Fill the pump-up sprayer with the mixture. Wet the deck boards with a garden hose and spray liberal amounts of deck brightener over the deck boards. Allow the brightener to sit for the recommended amount of time. Lightly mist the brightener while it is working to keep it from drying on the deck boards. Ratios of brightener to water will vary based on manufacturer.
Test a small section of decking to make sure that the boards have brightened by scrubbing a small area with the scrub brush. If the boards have lightened, use the power washer to rinse the deck brightener off of the decking boards. Use the same spray pattern as in Step 1.