ACV does not feed candida. Vinegar is to be avoided all together but ACV(the natural stuff 'with the mother') will kill candida. I tend to stay away from it because it is TOO potent to my taste and it will cause heavy die-off - and although killing a lot of candida is great - heavy die-off is hard to cope with.
Passing the spit test after taking ACV is not quite relevant. If you kill all the yeast in your mouth you will pass the spit test. But that does not mean you have killed all the yeast in your body - I personally had killed all the yeast in my body for a few months i was back on a normal diet. What is relevant is to find the reason why healthy candida changes into the nasty invading yeast - to me the answer is heavy metal contamination. And most people will agree it has to do with you ph being too acidic.
I see many post saying: "yeah I am passing candida". Well that is a victory but a small one. It means you are no longer feeding it, some of it dies. But you want to deal with the cause behind - getting rid of the acidic stuff that makes it proliferate.