I have a 12 year old Trex two tiered deck and have been using Corte Clean ever since it was installed to clean mold, grease, oil, rust, etc. For a few years in between, at the beginning, I have tried other products that the Trex Company recommended without the same success, as they were available locally at Lowe’s, Ace, etc. I tried them because I was in a hurry. They smelled so horribly of chlorine, the neighbor came over to complain! These products never really worked. Nothing else works quite like Corte Clean and I will never again use anything else again.