I have been using Corte Clean Composite Deck Cleaner for at least 5 years on my Trex Brasilia deck. Prior to using Corte Clean, I used to use a mixture of bleach and water combined with a cleaning solution that was once recommended by Trex, as well as, using a pressure washer from a distance. I wish I had found Corte Clean much sooner, because the other solution really took the color out of the decking and the power washer probably contributed also. The first time I used Corte Clean, it was a noticeable difference, as the black spots, green mold, leaf residue and grease stains near the grill were taken away by simply applying with a pump sprayer and then lightly scrubbing the deck surface with a brush. To achieve excellent results, you must follow the instructions, which are not difficult, but require patience. Also, the weather conditions, such as temperature and sunlight, should be favorable for this product to really clean well. I use this product each year to clean thoroughly in the Spring and then lightly in the early fall. What I love most about it, is that it seems to leave an invisible residue on the decking that activates in the following weeks after cleaning whenever it rains, which keeps the mold spores from returning.