I only offer my own experiences healthwise, this is what happened to my brother.
He once or twice tried to 'detox' by himself. He had audio and visual hallicunations, he developed paranoia, he became violent towards his partner.
Later, he lost all control of his bodily functions, he was so weak that my parents insisted he went to stay with them for a while, he fell out of bed and spent the night on the floor because he was too weak to call for help. (and I mean weeks later, not a long time)
Then he just stopped eating or drinking anything (he hadn't drunk alcohol for a month before because he just couldn't keep it inside him)
Then his body gave in completely.
If it was my father I'd want to know, and make my own decision about what to do.