You may not know what your bathroom tiles taste like, but your child does. A simple rule of thumb: if you wouldn't want to bathe in something, don't put it in your bath. Yet most people don't think twice about stewing their delicates in the not-so-sparkling waters left behind by harsh bathroom cleaners. Safe for septic tanks and cess pits, as all of the ingredients are biodegradable, also safe to use on natural stone provided it is sealed.