Fill a bucket with 6 ounces oxygen bleach and 1 gallon warm water.
Hose off the patio or deck with your garden hose, rinsing off as much loose residue as possible.
Dip a scrub brush or stiff broom into the bleach solution and scrub the deck or patio. Start at one end of the patio or deck and work your way to the other side, scrubbing in firm, large circular motions.
Rinse off the deck or patio as you clean each section to wash off the loosened residue before it dries back onto the patio or deck surface.