Your article got me wondering: is there such a thing as fermented turnip juice? I have had fermented cabbage juice before (they sell it in health food shops in France) and as you say, cabbage and turnip are related, so even if nobody has ever made it before, it should be just as easy (once you have the juice, that is!) and just as effective (if a little unpleasant taste-wise!).
Well, I make turnip pickles, I guess the juice would be the fermented juice. I will have to try drinking it, lol yuck, your right it does not sound all that great. I bet, though, it is really good for you.