Sigh back to where i started
It's probably not the baking soda. It's more than likely the salt and lemon juice. Both things that will dry the crap out of your hair and scalp and force it to produce more oils.
How often were you washing? How much salt and lemon juice were you using?
Logically, if baking soda and acv are bad for you (which I highly doubt as I've been using it for 6 months now and it's cured my dandruff and my hair feels awesome) why on earth would you think lemon juice was ok? Lemon juice is much more acidic than ACV not less.
That said, the sites I skimmed after googling about people saying bs acv are bad are full of speculation from people who have never done it themselves and proclaim that it can't even clean your hair. And the people who have used it and had bad results were putting baking soda PASTE on their hair, scrubbing it around, and not rinsing with ACV. Most of the sites even assumed you mixed both together for a chemical reaction.
All of that is ridiculous. And they all seem to be blogs written by housewives. Not people with science backgrounds. We've had a pharmacy tech explain the ratios. I'd trust a pharmacy tech before I trusted some blog site. http://www.dreadlockssite.com/forum/topics/baking-soda-and-sea-salt-ratios#.UBqYFaNWl8E
The very first site that comes up from my googling claims to be scientific and honest. Then they turn around and say that a woman using BS and ACV to successfully counter dandruff should instead use EXTRA STRENGTH HEAD AND SHOULDERS! What?! That shit is poison and I now have no reason to trust these people to tell me what is good for my hair and scalp. They are full of it.
Be careful where you get your info. SE used the BS and ACV for years and years before he started using the bars from dreadlockshampoo.com. I don't think his dreads would be so long and strong if the naysayers were right.