I guess I tend to be a purist but Dr Davis's advice probably works best if you follow his instructions. Of course if something else is working for you then that's all that matters.

Most commercial fermented foods do not stack up against the homemade kinds. Some of the commercial vegetables do if they are naturally fermented and sold in the refrigerated section of the grocery store. If vinegar is used to make them then you don't get the probiotic benefit. No commercial yogurt will stack up. The value of Dr Davis's homemade yogurts is in the long fermentation time, the addition of a prebiotic substrate and the use of particular strains that provide specific benefits, or at least that's the theory. I have been making both my own fermented vegetables (Dr Wahls has a great kimchi recipe) and my own yogurt using coconut milk, following Dr Davis's recipe and using the L Reuteri probiotic strain that he particularly recommends. The jars I use for fermenting vegetables are called Fido jars. They are not designed specifically for fermentation but they work well as long as you open them once a day to let the gases out. You can find them on Amazon and other sites as well. Mason jars can work well too.