What's the easiest way to clean duradeck?

Have you tried power washing it?

Use warm water and a stiff broom, scrubbing in a circular motion to loosen the dirt. Then simply spray with a garden hose (under pressure) to wash away the loose dirt and flush thoroughly with clean water

Thank you , but we are on a 3rd floor balcony, so we can not power wash or garden hose, makes it tricker, can't even dump a bucket of water on...

Then,soak it the best you can then scrape it off with a sharp putty knife ? Its a shame that ya can't use a power washer !

What I did with half of the deck so far, is use a orange spray cleaner and a brush, then wipe rinse with water, then steam mop over. It is a lot better. I was hoping there might be some special mixture that would help the dirt come up. It would be great if we could use a power washer...

Use mixture of 1/2 alcohol and 1/2 white vinegar. If you can't spray it off with a hose, you should just spray this on, let it sit for a while, then wipe with a clean cloth. Do a little light scrubbing to get in the creases.