Unfortunately I was one of those morons who selected Trex for our decking. The deck is now covered with those nasty black spots. I have tried all the recommended cleaners/brighteners to remove them (products with sodium percarbonate, oxalic acid, and sodium hypochlorite/bleach). Some have lightened but many are still very visible.

So (sigh) my only recourse at this point is to cover the spots.

I would prefer to use a semi-transparent stain since the deck is actually a mix of Trex and PT (the deck floor and handrails are Trex while the posts and spindles are PT. The idea was to protect little feet from splinters.) The PT is unfinished and would look great with a see-through stain. The Trex was originally "Saddle" color.

I've read all the recommendations about TWP but am hesitant to order it. Would the TWP cover the spots on the Trex?

Or would I need to use a solid stain for the Trex and a different semi-transparent stain for the PT?