Mr B

I think you misunderstand what a boundary is about. It took me quite a while to realise that a boundary is not about getting someone else to stop doing something I find unacceptable. A boundary is about how I protect myself from unacceptable behaviour from others.

So to answer your question "What good are boundaries to someone who has lost touch with realty?", the answer is "None". Someone who's lost touch with reality likely has no concept of the need of boundaries or why they're important.

If you recast the question to "What good are boundaries to a person who's sharing a house with someone who has lost touch with reality?", though, then I think the answer is different.

I understand you are not willing to leave your home. That's ok, but it does limit your capacity for personal protection somewhat. Let's look at this a different way. Say a stranger staggered up to your house, collapsed unconscious outside your front door and was obviously so messed up that they lost control of their bodily functions. You're not sure if they're drunk, drugged, sick or injured. Wouldn't you call an ambulance? I would. Sure, if they stink of alcohol then I might suspect they're drunk but I'm no doctor; I don't know. For all I know they might be perfectly sober but in a diabetic coma and just happened to have had a glass of whiskey spilled on them by accident.

So if your wife loses control of her bodily functions, and is so out of it she is incoherent and cannot be properly roused into consciousness, maybe it might be a good idea to call an ambulance and get some professionals involved in her care.

You cannot expect someone else to respect you. That's their business. All you can do is conduct yourself in a way that allows you to respect yourself.

Take care,
Mr B.