Liquor doesn't have carbs in it, even Captn' Morgan & Diet Coke. I'm not a gay man, but a straight chick and it's usually what I'll drink when low-carbing. It's my favorite even when I'm NOT low-carbing.
None of the straight liquors have carbs; rum, whiskey, gin, vodka, etc. Stay away from the liquers though - tons of sugar. Beer is usually pretty high. Lite beers can be anywhere from about 3-6. The new low-carb beers has about 2.6 and I think it's called Michelob Ultra. I've heard it's pretty good from other low carber's.
I have Cpn Morgan & Diet Coke and stay in ketosis just fine afterwards - but get drunk on just 2-3. I also usually get a pretty bad hangover from drinking when low-carbing, especially when I'm in deep ketosis.
You'll find that the dehydration from drinking will make you show purple pretty easily. If you're still in the pink range two days later, you probably haven't done any damage.
The biggest problem with drinking and long-term low-carbing is that it's really easy to rationalize eating a bunch of crap when you're drunk.
Fawn