What exactly do "White Vinegar" or "Lemon Juice" do? What other such "tools" exists to affect e-juice flavouring and what do they do? How is Ethyl Maltol, Stevia or Brown Sugar different from each other? I realize there are lots of threads on this, unfortunately 4 hours alone can be spent weeding through 1,000 off-topic chatter posts making it very time-consuming to find and get down to straight unabridged talk. Any input is appreciated.