This product isn't just good - it is SUPERB!!! I told the CorteClean customer rep that I purchased their product because it was one cleaner listed in the TimberTech maintenance instructions. I had used the cleaner twice - each time scrubbing the deck using a stiff bristle brush. However, within a couple of months I could see some black mildew spots. The CorteClean rep recommended I should be lazy - put a couple of scoops of CorteClean in a gallon of water, spray the deck liberally, then sit down and have a beer and let the deck dry....the next rain will activate it. So I followed his recommendation....2 days later it rained....and 2 months later the deck still looks spotless and brand new!! The hardest I worked was to pump the sprayer....and open a beer. You cannot go wrong with this product!!!