Valspar wood cleaner

Five days ago cleaned 9-month old new cedar pergola with Valspar Wood Cleaner. (In South Carolina). Had lots of gunk and graying. And there seemed to be a white residue left on some of the wood. Started to gray again after two days, then rained, and expecting rain for another three days. Want a grey stain (either semi-transparent driftwood gray from Armstrong Clark or solid stain Coastal Gray from Restore-a-Deck. Question 1 - Do I need to clean and brighten again?  Question 2 - What is the best product if Question 1 is a yes?  Question 3 - If I use a semitransparent stain and do not like it, can I stain with a solid color over the semi-transparent stain, and must it be the same brand?