Washing stains off trex decking?!

I had a customer call me this past weekend telling me that her children went into the pool and chlorine dripped off there clothes on her brand new $13,000 trex deck! I went this morning to investigate the situation, the decking is a darker grey color and the stains are a light milky white. Im not sure exactly if its chlorine or coloring from the clothing that dripped off but either way, has anybody ever dealt with this? Ive washed trex before and cleared a ton of mold and mildew but never dealt with any type of staining. suggestions?

Pool water dripping from a bathing suit is not going to stain a new composite deck. There is obviously something else that made contact with the deck. Maybe her husband dripped straight SH onto the deck while chlorinating the pool. Post some pics so we can get a better sense of what your trying to explain.