We don't let them in the house but I was working in my shop today (14x24 with a 24x32' open pole barn adjacent) and heard some hens talking and turned around to see six of the ladies coming in to visit. I softly called them and they all came in and had a look around....hens are sooo sweet, they have an innate curiosity about everything.
I have seen film of a woman who had a silkie as a pet, kept it indoors with a diaper, bathed it, snuggled with it so I guess if you're into that kind of thing it's possible. I doubt you could housebreak one but as long as you want to deal with one in the house, it's not out of the realm of possibility.
I don't know but I once had a canary that was housebroken! Really! He knew to go to a folded peice of newspaper to do his business. I think he felt it was the only thing he was allowed to poo on since newspaper lined the bottom of his cage??? Very convenient for me though.