First of all, I want to give you an encouraging hug for all you went through this weekend...a very, very tough break, and I'm sorry both you and your girl went through any of it.
Secondly, I know what it is to live with a chronic alcoholic/addict, and I can tell you some things quite concretely. If your daughter does indeed have an addiction, there may be little if anything that will "scare her straight." Alcoholism/addiction is a disease, an actual illness...and you did not cause it, you can't control it, and nothing you can do can cure it. If your girl genuinely has this disease, it may be necessary to distance yourself from her, so that you do not allow her illness to make YOU sick. Sick in the sense that you let her disease control YOU...often, those of us who love an addict/alcoholic let the behaviors and sickness of the addict/alcoholic run our lives. This is when we must learn to live for OURSELVES, and how to make our OWN lives manageable, with or without the alcoholic/addict.
To keep it simple, take care of YOU. It sounds like treatment is a step in the right direction. But I'd proceed with cautious optimism if she truly has a problem...relapse is a natural part of this disease, and many people relapse MANY MANY times. However, you cannot sit around worrying or wondering if she is going to slip up, or when you'll have to go through this nightmare again...you must live for yourself, and learn to let things be. The only people we can truly manage and control is ourselves.
Big hugs to you, and best of luck.