What would you do if an office coworker came to work every day with body odor that fills the room?

It's a small newspaper company with an elderly owner who suffers from cognitive decline and is not there. The GM has a history of not addressing problems unless they bother him personally. He is removed from my department and I have had experience with him ignoring problems I have drawn attention to. My dept. manager is the bigger problem: she and the company benefit greatly from the work of the employee in question, so they permit him to come to work without showering. His body odor is sometimes bad enough that people in the neighboring department complain. Nothing was done. He once wrote a profanity-filled self-loathing diatribe in the system that was an obvious cry for help and it was ignored. Someone found it and brought it to the manager. She read it, I read it, we discussed it and she put it in her pocket without handing it over to the GM. That was the end of it but these are signs of possible clinical depression or mild mental illness. Any time I bring it up with the manager, I am the bad guy. She enables him because he simply cannot be replaced. He is a good employee and there's no way they could find someone as committed and competent as he is but there are problems that are just flat alarming and being ignored. I feel like I have no one to turn to: I feel like I'm screaming and waving red flags over a problem nobody has the moral fiber to be proactive about because there is no HR department or procedure in place for filing grievances. I can't confront him, give him soap or hose him down, so what do I do?