I had a customer ask me to clean their Trex deck with Corte Clean. I didn't really want to mess with it but I agreed to try it before going my usual route. They bought the product and I brought a pole and a deck brush. I mixed it at a slightly stronger ratio than recommended because their deck was pretty spotted with mold. I brushed about a 3 ft section for 10 minutes with mediocre results. The customer looked at it and said, "Well, it looks better doesn't it?" I said, "Yea, but I'll be here for 2 days if you want me to do the whole thing this way and that just means a lot more $$ in labor." We ended up cleaning it with a strong house wash mix and have done it another time since with great results.