+1 on the timber oil. The same company makes a problem solver product that helps prep existing wood, just spay or brush on and pressure wash off.

Our new deck is not Cedar, but here's some info ...

If you pressure wash it, you'll end up 'raising the grain' and have a bunch of 'fuzzy' crap to deal with (sander). Pressure washing Cedar removes some of the wood and leaves an undesirable layer of 'stuff' that you then need to sand down. Plus, you've removed some of the water repellant properties of the Cedar
You can try to 'lightly' pressure wash it, but I suggest you use a 'cleaner', such as TSP and a big brush. Research it, it works just fine with a garden hose and some scrubbing (lots of scrubbing :wink:)
Wash down all the cleaner you used so your lawn/garden etc doesn't die out for a year or 2 :wink:

Let it dry with good sunlight for a few days, and seal it with some Cedar deck sealant
Plan on having a day or 2 of upcoming good sunshine before you apply the new sealant - it has to dry before it gets wet
And save yourself the grief of brushes - use paint rollers wherever you can after you've covered all the tight spots with a paint brush

It took 3 of us 2 hours to seal our new deck with 2 coats

I'm going to clean the deck today. There's some vleaners that take the grey Mildew out of wood and ill hose it down. Not pressure wash

Thank you

+1 Sikkens-cetol 1. Ive used it on several projects over the last 15 years, comes in various colours.
I like it a lot and recommend.