I really feel for you having to see your childrens' father in this state. I hope some of the other 15 people had a word with him too and not just with you.
I hope by talking to you about this, these people are not suggesting it is your responsibility. It is not.
Raising the subject with him can do no harm. It is unlikely to do any good either.
A good friend of my husband's was in a terrible state some years ago. He was jaundiced. He came to live with us (disaster). His wife had paid for him to go to rehab 3 times by this stage. She flew over (at my request) to try and talk him into getting help. She was gentle and loving with him. Then I got his sister to come. She was a bit tougher but still treated him with love and compassion. Everyone was asking him to PLEASE get help. Nothing got through to him.
Eventually my husband marched into the bar one day, grabbed him by the scruff of the neck, kicked him up the backside and screamed at him "look at the f@@@ing state of you!! Do you want to die? Why don't you F off out of lives and sort your s@@@ out"
That really shook him up. Within days he was on a plane home. He got clean. It took a few tries but he has now celebrated 10 years clean and sober.
I don't know if this story is at all relevant. In my friend's case all the sympathy and compassion in the world did not help. Treating him the way he was treating himself seemed to be what worked, for him.
PS I am not condoning violence or agression. This is a true story and possibly a little bit extreme.
As they say in Al anon, take what you like and leave the rest