Heh, even an oral cavity search doesn't always work. My son is an expert at ditching meds, and he's eleven years old. I'm confident that a grown woman could ditch them.
I don't know of any treatment which will work on the truly unwilling. Extreme aversion therapy, maybe, but even then you'd have to force her through the therapy somehow. That is probably not going to happen.
The Vivitrol shot is an interesting idea, if she's willing. It is better than nothing, although not as good as the targeted approach. Let me look something up here.
Hey, yeah, here it is. This from a forum called Crippling Alcoholism, where people who have decided to just live with their incurable alcoholism hang out. As they put it, they "accept their lifestyle choice."
http://www.reddit.com/r/cripplingalcoholism/comments/1cyhx4/my_experience_on_naltrexone/So here's this guy who assumed he'd drink at least ten drinks a day until it killed him, getting the shot, and finding to his own surprise that he's suddenly drinking less and even finding other things in life.
If you read the whole thread, there's a lot of arguing about whether or not this counts as Sinclair. Short version: if you drink daily then you take nal daily, so the shot counts.

You'll also see that he eventually switched to oral nal because he became capable of alcohol-free days, and -- this part makes me happiest of all -- that he started thinking about the future and about creating a life instead of just about his daily drinking. If that guy can be cured, surely your wife can.
I still want more info, though. How much does she drink? Does she want to quit or cut down? Which, and why or why not?