How does apple cider vinegar react with baking soda?

Sorry if it's a stupid question. :p I am thinking of making an oatmeal shampoo homemade and found an extremely simple recipe online, but read somewhere else that apple cider vinegar can act as a deodorant and can keep a dog's coat shiny, but before that I'd like to know how it reacts with baking soda, if it's safe to use, and if it is at all toxic. Thanks for your answers in advance.