Prep a 4 year old rough sawn deck

 I have a 5 year old deck made from rough sawn 2x6 lumber. originally stained with Super Deck oil based semi transparent stain which is no longer available. After two years, restained with Messmers water based stain which was rendered an opaque brown color with no transparency. I want to get back to a natural semi transparent finish and am considering Armstrong Clark. Do What is the best stripper to use, or will a cleaner do the job. I also use the under deck are and all the joists and bottom of the deck are stained the right color. I don't want the stripper or cleaner to streak that area.