Restaining Old deck with unknown finish
We recently moved and have a 12 yr mostly covered front porch deck and stairs that badly needs to be cleaned and restained. Most of the exposed wood nearest elements is bare (silver wood tone). The parts of the deck nearest siding and under door mat still have residual stain, of unknown origin (natural reddish clear stain or sealant). The wood origin is also unknown, but likely inexpensive -- pressure treated wood.
I've found info for cleaning on archives of this board, but should I strip, or just clean and restain. I'm leaning toward Cabot clear stain...not sure about oil or water.
Here is a picture...the best I have at the moment