Yeah alcohol is everywhere. Sounds like this may be this first type outing for him since getting sober. Maybe he just wants to socialize, maybe he is trying to figure out his new normal. Maybe he will figure out he is bored as hell and next time will do something else. There are a myriad of ways for that to go other than he will drink which is possible.
AS to housecleaning - I too am the messy one. RAH is OCD. Here is how we handle it - I do contribute to cleaning the house I am messy, but not filthy. Anything that goes above and beyond basic cleaning is up to him. I think you are facing an uphill battle on this one. No one has ever been able to change that about me (believe me my parents tried really hard and no go). I don't give a sh!t if a coat hangs on the back of a chair or in a closet. Housecleaning can be a real sticking point and can cause a lot of arguments. Hiring a maid may be the way to go here though I doubt it will alleviate his messiness completely (aka picking up after him). Maybe you guys can come to an agreement about some things - for me leaving food around or dirty dishes is gross. That I won't do and I have done some things RAH has asked such as not cluttering up counter space with my crap. Pick and choose your battles.