I wouldn't use the old sand. I would just pitch it and buy new aragonite sand from the pet store. Old sand could have all sorts of crap in it and it can be difficult to clean.
As for the rock, I wouldn't go so far as bleaching it. That's unnecessary for dry rock. I would hose it off with the garden hose to dislodge any dust and dirt. Then when you put it in your tank, be sure to add a little bit of dechlorinator.