Vertical vs horizontal Behr horrors

I have a large Cedar (not pressure-treated by the way)deck that was painted with the horrible Behr solid deck product several times by the previous owner. After many weeks of sanding all of the horizontal surfaces the deck is now clean on the horizontal parts. My question is really about what about all the vertical parts - most of the uprights (spindles) look okay as to all of the beams holding up the deck; Can I now stain over the vertical parts with the Behr still on it with a Sikkens solid product?