I pull wood from saltwater all the time here, but it far more important to identify what kind of wood it is. Here in the Northwest it's likely, if it's in saltwater, and SUNK, to be waterlogged pine, douglas fir (not a true fir; it's own species), or arbutus.
I don't even worry about it. In it goes. Any marine worms that dare show their head the Oscar gets anyway. But I wouldn't do that if I had $1,000 fish!
Down where you are you've got lots of redwood. I wouldn't try an oily wood like cedar. Too many oils.
Boiling is good. Bleach for what and why? Bleach kills, all right. It kills fish.