Hmm, that's an interesting idea, but wouldn't cigarette smoke be essentially sterile? The tobacco is burned before it is released. Orchids are really good at cleaning the air, too.
Still, it's a shame that's all their orchid house is being used for. Isn't there someone you could alert about this? Just maybe diplomatically mentioning to the boss that some very valuable orchids (that huge one would have sold for hundreds of dollars) have been let die, and you think the person in charge there is not qualified to care for orchids? What are they doing with all the keikis anyway? Selling them?
Busch Gardens does have wonderful gardens, and a really great zoo, too. But sady, you can't go in just to see those things without paying the outrageous entry fee for the amusement park.