IMHO, a simple no thank you for the smoke should suffice. No explanation necessary.
Unless the event is advertised as BYOB, so as not to insult the host's hospitality, I drink what is offered or say no thanks if the proffered beverage is undrinkable swill. In the parts of the South where I was raised, bringing your own upscale drink would often be construed as elitist, snobbish and rude. If I know the people well, I might bring my own but , I'm certain to bring enough to share, even if the host is a close friend.
On the other hand, when I host informal events, like a herf, I let my guests know what I'm offering for beverages, usually decent wines, craft beers and fine scotches - both blends and single malts. If someone hints that the menu doesn't suit there tastes, I'll let them know that they are free to bring their favorite beverage.
Lots depends on the crowd, personalities, type of event. But a simple "no thanks" is always good eteiquette and you owe no explanation for the declination.