Removing BEHR Transparent Waterproofing Wood Finish

My 1200 square feet of clear heart redwood decks were restored a few years ago after almost 30 years of simple yearly cleaning.  The contractor pressure washed and sanded the decks.  After sanding, the wood looked almost new.  The contractor then applied BEHR No. 400 transparent finish.  A couple years later the contractor returned to pressure wash the decks and applied another coat of the same product.  Within two years the decks looked like they had been painted with tan paint.  After watching the BEHR finish deteriorate since then, I to refinish decks myself.  I chose Wolman Deck Strip for the job.  After two applications, each followed by pressure washing and brightening with Wolman brightener, the wood showed a lot of dark areas and dark streaks among lighter areas.  I hired a local handyman to sand the decks before applying an oil-based stain/sealer.  After several hours using 36 grit paper on a drum sander, the handyman was able to get down to clean, red redwood over about 200 square feet.  At that point he stopped and advised me that the paper was loading up with residue from the remaining old finish, and that the decks should be stripped again before attempting to finish the sanding.  He recommended Restore-A-Deck stripper with booster, followed by brightening.  I have ordered the stripper kit, but I am looking for input on the prospects that this will solve the problem.