phaethona--I'd be really interested to hear how the experiment goes. I don't see how it could hurt to try--ACV is cheap, readily available, and completely non-toxic, so even if it doesn't work you won't have lost much. And I would not be at ALL surprised to hear that it works.
Our society has become so thoroughly flooded with the (paid for) messages from the pharmaceutical companies that we've forgotten we once used to treat everything at home, and most of the time it worked. Not only that, but we were often healthier for it. Sadly, as a result, we've lost nearly all the traditional wisdom that was once passed from mother to child about how to heal ourselves, and now we automatically turn to the (expensive) pharmaceutical answer, often at great cost (but monetarily and physically). This is not anyone's fault per se, just a natural consequence of an industrialized world in which the companies with the big bucks get to construct the messages everyone hears.
Another example of this is the fact that many people are amazed to learn that even the common cold was once a thoroughly treatable condition, one that could be healed very quickly if you had the right medicinal ingredients (easy to grow in a backyard) at hand and a little time. Unfortunately, most people *don't* have the right ingredients any more, because they're hard to find. They look a lot like the apples, carrots, and garlic you buy at the grocery store but they harbor powerful compounds that knock a cold flat. They even go by the names "apples," "carrots," and "garlic," but you'll only find them at local farms or, sometimes (if you're careful and ask where they came from) farmer's markets. Industrially produced versions of the same things can still help, but they won't pack that punch because they've been fed on depleted soils by nitrogen fertilizers that don't contain the compounds the plants need in order to produce the medicinal compounds *we* need.
Anyway, if you want to try it the next time you have an upper respiratory infection (or a cold), go to your local farmer (or farmer's market--but make sure the produce is in fact local) and purchase fresh garlic, aromatic apples (any variety will do so long as they smell really strongly like apples), and some carrots (these don't actually have to be local, but it doesn't hurt--at least go for organic if you can--they're not much more expensive than standard). Take them home and put them through a good juicer. About one apple to two carrots to one clove of garlic is a good mix, but add more garlic for a stronger punch and faster action. Drink. Feel better instantly, and completely well within a day or two. Drink once or twice a day. If you can grow your own carrots and garlic (easy) and apples (easy but takes longer, lol), even better.
I was amazed the first time I tried this and it WORKED. Years later, and many other remedy recipes under my belt, I'm no longer surprised. Pharmaceuticals are almost all derived from plants and animals that we can access ourselves, with the chief advantage (to the pharma companies) that after processing they are then patentable which means someone can make a crapload of money off them. Which they then use to market the product to us so that we think it's better than the product we could make for ourselves.
Sorry for the soapbox. I am really passionate about this stuff. It's the REASON I have ducks--so I can have my own nutritious eggs with all the fatty acids in the right proportions and the trace minerals and all the other nutrients that store-bought eggs lack, plus the knowledge that my ducks get to be ducks not mindless, suffering machines. Eggs are powerful medicine too in their own right, but only if they're *good* eggs.