I do want to be clear that I don’t expect an immaculate room all the time. Rooms have to get immaculate a minimum of once every other month (or bad things happen). Day to day, they have to not look like a bomb went off. Regularly (2-3x per week), they get picked up to 85% clean.
Kids can’t just be told “clean your room”! They have to be taught. It takes years, literally, to learn to clean quickly, efficiently, and thoroughly. Everything from putting things away, designating places, organizing to prevent messes at the outset, learning what to keep and what to discard, when to discard, and why to discard–then there’s the actual CLEANING, like sweeping, vacuuming, dusting, mopping, scrubbing. All of these are real life skills.
A truly messy bedroom WILL be hard for any kid to function in. It’s harder for kids with ADHD, and they’re more prone to messes. Getting a kid to adopt a habit of putting everything back will do wonders. But again, this is harder for kids with ADHD, too, because the mental overhead is so much higher.
If you haven’t TAUGHT your child to clean, he’s not going to just pick it up because you say, “clean your room.” You’re going to spend a lot more tie teaching him to clean than to clean it yourself for a long time.