why does baking soda and vinegar unclog the drain?

I have a book on general housekeeping that discusses natural cleaning methods and why they work. Baking soda being alkaline can break up grease clogs in drains because grease is acid. For that reason it can also be a useful cleaning agent for lots of situations. Adding vinegar is for producing the reaction that contributes to the dislodging of the clog but the vinegar can also break up other kinds of material in a clog, that part wasn't clear to me, I guess I could go read it again. She also says that baking soda in reaction with the grease will produce soap. You have to do it frequently or repeat it many times if the clog is really bad. Boiling water is of course a big part of the treatment, as it melts grease.For Taz: There are quite a few sites you can find on Google that describe how to clear your vents. Here's one. You do have to get up on the roof and they do warn that you need to take lots of precautions. It sounds to me like it would probably be worth it to hire someone for the job who is used to working on roofs.

Well, I misremembered what the book I mentioned actually said. Par for me lately. But anyway there are two situations being addressed and different levels of the problem in each case too. For just keeping clogs from forming plain baking soda is recommended once a week. Dumping half a cup of it into the drain and letting warm water drip into it so as not to wash it down but get it to work on whatever grease might already be there. A stronger treatment would be sodium carbonate rather than bicarbonate, or "washing soda" same basic treatment.It's clogs where you use both soda and vinegar because you need the reaction to break it up. Two or three treatments may be necessary and if it's a really bad clog you'll have to resort to something stronger.Nevertheless the principle that the alkaline soda breaks up the acid grease is still the explanation for how it works.And I'm relying on my memory again so may have to do more reading later.