Haha, this is so funny.
I go through this routine every time I meet new people, because I really don't drink!
It has taken me a while to be able to explain this to people without making excuses for it and feel like a little boy about it, but I've managed to turn that around to being a real DHV thing, just by being honest about whom I am.
I simply tell it like it is, I don't like the taste of alcohol, or cola either, and just don't drink it. It's not a religious or intellectual thing, I just think it tastes like drinking gasoline. Why would I do that? I still have a great time without being drunk, and I don't look down at people who enjoys it.
My friends have accepted this and they all respect it, so I'm even included when there's a drinking game going on, because I still provide great social value and manage to keep the score, hehe.
There are actually quite a few useful things that I've found about being someone who doesn't drink.
# Since I don't get drunk, people rely on me in small ways to be the one who watches out for things and makes sure everything is all right. This gives me a bit of an authorative and mature status, even if I don't really do anything. This is not only good for DHV, but sometimes it can also mean that people trust their valuables and morals with me. I'll hold on to cameras, mobile phones and prevent people from doing things they'll regret in the morning, like calling their exes and swimming while drunk.
# Since people know at leas one person will stay sane and sober through out the night, they can focus more on having a great time and let loose more.
# Sometimes people likes to challenge you, and would like to see you drink all kinds of stuff, either just to se your reaction, test your opinion or attempt to get you dunk. If you're smart you should turn this into a proposition game, and ask what's in it for you? If you're brave enough and the situation is right, you could even be sneaky enough to point at your interest and say "Sure, I'll drink anything you send my way, if that girl agrees to kiss me first".
Some good lines to go:
"Don't worry, I won't think any less of you for getting drunk and having a good time. I'll even buy you a drink if you tell me something interesting about yourself."
"So, what are you drinking? Could I have a sip?" + "Yeah! (looks surprised/impressed) That was horrible! (Big smile)"
"What I drink? Water, soda, tea.. milk! I love milk. Best drink ever. Oh, you mean this? (holds up glass) Uh.. I have no idea actually. A friend gave it to me and wanted me to try. Taste like horse piss, but apparently it makes you have as much fun as he does. Haven't seen him in a while now though. He said it would make all the ladies look really attractive. I think he's on to something actually, because I have barely touched this stuff and you look amazing! What does your drink do?"
"I'm not against drinks, I just haven't fallen for anyone I've tasted so far. Maybe I'm just picky, and haven't had 'the one' yet? I'm open to suggestions though, and I'll try anything once."
"I was actually thinking that maybe I should drink something just to get a buzz going, but as it turns out, I feel strangely light headed just sitting next to you. Do you mind if I hang out with you for a while?"
I haven't analyzed any of this against PUA teachings, so if you think there's a lot of AFC misstakes in here, feel free to let me know. I don't drink for real, so I've been forced to work on my DHV skills in regards to this fact just for general reasons, and I've said a lot of this in a very spontaneous way, without really trying to pick someone up.
I hope you'll find this useful, and remember, it's totally all right to like milk!