"It doesn’t have to be this complicated."
That's very true, but i'd say that the most complicated thing you're dealing with is being OCD. That's why you have to clean the carpet so often, that's why he has to fret about dirty sheets that aren't dirty. The rest of us DON'T have to do that. You might get a clue about it when he says “Carpeting is gross. End of story.” No. Carpeting is NOT gross. Not if you're healthy it's not. There's nothing gross about it. Here's a little test you can do: Ask him What's Gross About It? If he can't point to something that's either visible to the naked eye or papable to the touch, that means it's in his head, not in the carpet. So your answer is Yes, there is absolutely a better way. He can grow up, OWN his own unhealthy perceptions, and simply accept the burden that comes with them.
When my vision started to deteriorate, did i compensate by complaining about how blurry the world is?