Vinegar is a mild acid which disinfects most surfaces, and unclogs things like shower heads. It will also clean mould and mildew.
Liquid castile soap is good for any type of cleaning where you need soap.
Salt is good for rinsing your throat if sore, (do not swallow) and for setting colours especially deep pink, reds and deep blues prior to washing. Salt can be used to clean grubby cutting boards, just rub in with some real lemon, let sit for a few minutes and then rinse with very hot water and air dry.