Would it be possible to provide us with some pics please? That would help us see what is going on better.

Sorry to seem dense, but I don’t understand what you’re trying to clean with a hose. The outside or the inside? The inside appears to be carpeted and has electric inside the walls so you must be talking about the outside?

I'm asking about the inside. It's indoor outdoor carpet over concrete. I would remove the carpet. Any outlet would be converted to the type you have outside that has protection from the elements. You can't see all of the inside but there's a lot of square footage between walls and vaulted ceiling that get really dirty. It takes forever to clean by hand.

littlebug... This pic shows the back of the waterproof housing the exterior plug sits in. (on the left side of picture) I would use something similar on the ones facing the interior.

Even if you replaced the outlets with outdoor capped ones, I still wouldn't try power washing it. Your siding is that easy to peel off, it could be easy to pressure in. And no to running a hose either. I can see from the staining you already get water in that wood, you probably don't want to soak it on purpose.

What is your current cleaning process? Do you clean it in the spring to clear it of fall and winter ick? Clean in the fall to clear out summer pollens and dust? What are you doing/using for cleaning currently?

That looks like a very inviting space!

My Mom had a screen porch that she used daily, all summer, and she was a bit of a clean freak. Hers had pine on the inside, and carpet.

In the fall she covered the carpet with a sheet of plastic; in the spring she folded up the plastic, did a quick vacuum, and she was ready to put furniture out. Her walls did not show dirt as much as your white siding, however. I might be tempted to give it a good clean in the fall, and cover it for winter, see if that helps.

Thank you for the feedback. I'm usually cleaning it in the spring every year. I could see how pine paneling would hide some of the dirt but mine is all white. I currently scrub the whole thing down with soapy water and wipe dry. This is a big space with a vaulted ceiling and it gets gross so fast. For those of you thinking I'm just being fastidious, here are some up close pics of what I'm dealing with. There has to be some way I can add a drain, maintain the integrity of the wood framed pony wall, and pressure wash this whole thing.