I'm sorry to know of your Dad's situation but very glad he is being professionally supervised.....
If you read the link already posted....you will see that not one of us had the same exact de tox experiences.
Generally....it takes 3 to 4 days to de tox...and it can be done safely. To keep drinking because you fear de tox is a lot more harmful.
I hope you will find your way....recovery can be awesome....