What would you recommend for safe toilet cleaning products?

As a general rule, the more natural the cleaning product the better. Synthetic surfactants designed for toilet bowls for example, which often contain chemicals synthetic dyes, chlorine bleach, ammonia, petroleum-derived ingredients, and other harmful ingredients, such as Triclosan (prevents mold growth) are hazardous to a healthy bacterial eco-system living within your Fuji Clean system. Ideal choices might include white vinegar, Borax, or lemon, which contains citric acid.