Guy Refusing To Leave My Boyfriend's House

Location: Missouri

My boyfriend rents a house with a couple of his friends. He's a manager at a grocery store. A little over a year ago, he got a new employee who was down on his luck, so he invited the employee to stay at the house. The guy sleeps in the living room. A few months ago, he walked out of the job because my boyfriend had to write him up for leaving his shift hours early without talking to anyone. The guy hasn't had a job since and refused to look for one. He contributes nothing towards bills and doesn't clean up after himself, let alone anything else in the house. They all want him gone, but he LITERALLY SCREAMS that he knows his rights. He does receive mail there, so we know that there's probably nothing that can be done. The landlord doesn't want to get involved, not that he's involved with much of anything, like repairs. Is there anything they can legally do to get him to move out? I offered to "mean girl" him out (I have a lot of anger towards people like this, as I used to be homeless and never took advantage of the help I got), but my boyfriend is trying to keep things civil.

They've already blocked him from using the Wi-Fi, but are there other things they can legally cut off? Like the washer and dryer or putting a lock on the fridge? I know they can't block him using the utilities completely and they can't lock him out of the house. There's a laundromat down the street from them. The rest of the household is upset for obvious reasons, but their utility bill was $400 higher than usual this month (which is insane and they don't understand why it's so high) and he's the only one who's home all the time.

ETA: He's been living there for about a year and he NEVER leaves the house. He has a mental health counselor who does house calls and brings him food, but this organization doesn't work with uninsured, non-paying clients for longer than a year. He's only been with them for a few months. I suspect the organization is also paying his phone bill. I also wanna say that I'm not advocating putting people on the streets. Like I said, I was homeless for several years. I'm just not okay with people taking advantage of others' kindness.