The three C's:
You didn't cause it
You can't control it
You can't cure it
Unfortunately, your best efforts will have no long term impact on making his drinking stop, so you're better off putting your energy into something more productive.
My ABF (alcoholic boyfriend) would constantly tell me how he wanted to stop, he knew he drank too much, but he wasn't an alcoholic and didn't have to go to AA or anything, he just needed my support. Every time he relapsed he told me how I need to remind him of the awful hangover the next morning, or be more forceful telling him not to drink, or this or that or the other thing, I don't know how much influence I really have on him, etc.
Whenever I "lectured" him about drinking I always did it kindly, so that he wouldn't feel the need to hide alcohol from me, and he was usually honest about how much he drank. (When he drank a lot he always underestimated, but a large part of that is that counting abilities start to fail when you're drunk. He always kept the bottles to show me, so I always fixed the math). I would hide newly bought bottles, so that they wouldn't be visible and cause temptation ("Well, since it's here" was frequently a reason he drank), but I would fish it out if he insisted he had to have it, because I thought at least I'd always know how much he was drinking, and when he calmed down I could help him walk through it.
But it didn't get better, it got worse. I would remind him, I would beg him, I would insist, I would refuse, I would tell him that I could remind him not to drink but I couldn't make him stop, he had to do that all on his own - he accepted all these things, but still drank.
Everything I did had a minor, temporary impact, and I started thinking that maybe this time it would work (especially the time he went 19 days) - but it never did. There was always an excuse to drink, and always a reason why it wasn't his fault, it was mine... But none of it was true.
When I kicked him out of the apartment, he went to AA meetings all day, and eventually allowed himself to be checked into inpatient rehab for detox and then alcoholism treatment. He's out now, and I am 100% certain he will relapse, because the whole time he was in he wasn't interested in getting better for himself, he was interested in getting better "for me" so that I could "help him not drink anymore". Nothing was about me anymore, everything revolved around him and what I could do for him.
It wasn't until I removed myself from the situation that I realized just how much negative impact he was having on my life. Last night my car completely broke down on a major highway, it took me four hours to go home, and I had a great evening in spite of it because I discovered I could go through something stressful without having to put my own feelings aside in favor of a drunk alcoholic screaming about how it's not my fault but actually it is.
In my case, removing myself from the situation was kicking him out of the apartment (he's not on the lease, it's not even his legal address) and telling him I needed time with no contact from him. In your case, it's whatever helps you detach (with love) from the situation so you can get your thoughts in order and put your life back on track to where you feel it should be.
You can't help him unless he truly wants help. You need to forcus your efforts on yourself, and your kids, and let go of the things you cannot change.