There's a human rights concern leaving them in to wallow in their filth. Nevermind the expensive and depressing reality of dumping them in some strange tiled house. I also can't imagine them appreciating strangers forcing themselves in to spray everything.

I think OP was trying to get at the sad reality where severe mental illness is treated with some sort of loss in agency. You're still forcing some sort of solution they may not want and may work to sabotage.

You could advocate for encompassing services (e.g. regular visits from a nurse) but you'll quickly arrive at modern psychiatric facilities if for no other reason than scale and cost.