There at least two considerations here – the consumption phase, and the digestive/expressive phase.
Masking smell at ingestion:
- Many herbal cocktails will help mask the scent of alcohol on the breath. Avoid the fruitier combinations.
- Jello shots (done right) pretty much hold onto the alcohol until the digestion phase begins, minimizing the amount that gets "locked in" at the mouth/tongue/throat.
- Beer and straight liquor, of course, are both terrible as far as masking goes, and should be avoided if this is of primary concern.
Masking smell pre and post-consumption:
- Activated charcoal (~$5 http://amzn.to/jEob5F), the type more commonly used and prescribed for reducing body odor, helps a great deal. A lot of what one thinks of as "alcohol breath" actually emanates from every expressive pore in the body, including the lungs, and mouth – but also the sweat glands, and even the skin itself! To oversimplify the science, it's a bit like a bloodstream air filter, or a kitty litter box for your drinking habit – and seeing as both deer hunters and models seem to agree on this one for masking unwanted scents, I'm sold!
- Sodium Bentonite Powder (~$13 http://amzn.to/iDcCkm), used extensively in various skin purification and even some digestive "cleanse" programs. It basically works like the charcoal, absorbing toxins in the bloodstream before they have a chance to exhaust through various organs. For bonus points, also try calcium bentonite powder (also known as 'Psyllium Husks", and see which works best for you personally.
The best bet? Take some activated charcoal before you go out, indulge in a few Mojitos, and arrive home smelling of pure innocence. Even so, best to double-check in the restroom mirror, on the off chance some of that stripper glitter has rubbed off on your face – otherwise it won't really matter how much you had to drink…