OxiClean - Outdoor Multipurpose Super Concentrated Cleaner - Makes 2 Gallons - Stain Remover - Driveway Cleaner for Concrete - Degreaser for Cement and Brick (2 PK 6oz Bottle = 2 Gallons)

So I have this deck this hasn't really been taken care of. It was essentially black and coated in algae. I've pressure washed this deck bunch with various deck solutions, and this is how it's come out. Last time I washed through not much changed so I want to move onto the next step. I used https://www.amazon.com/Krud-Kutter-Pressure-Concentrate-Cleaner/dp/B005FMZ53A and https://www.amazon.com/dp/B0C1VXQRG7 (didn't use bleach cause I live on a creek). Can I just stain this or is there anything I need to do prepare? I saw a post of someone using Cabot Timber Oil that looked great, but theirs was a new deck whereas mine is not. Is that a bad idea or should I be using a different type of stain?