Hi there,
I've used caprylic acid in over 15,000 cases and not really found any issues with kidney toxicity to be honest, it works, but musty be used wisely and in conjunction with other antifungals for best result.
Colloidal Silver is excellent and should not really affect the beneficials, you'd be surprised how many "foods" affect beneficial flora like even a small amount of alcohol or soda. Yeast will not benefit from a diet rich in fresh produce, especially the greens, and I certainly agree that the starchy carbs (sweet potato, pumpkin, parsnip, potato, etc.) very much affect candida, especially during the first phase of treatment. You may like to read the 200+ page section on diet and nutrition of Candida Crusher, my book, which is being formatted and will be available online soon. It looks to be around 600 pages + once formatted and will be the most comprehensive book published to date as an e-book on candida yeast infections. It will answer a lot of people's questions and lay plenty of candida myths to rest.