I drink alkaline water and use it to spray my throat to kill off the digestive enzyme pepsin. I also use the alginate Gaviscon Advance, UK version, which stung at first from its sodium but now is soothing. Low acid, whole food diet is helpful for many people, maybe for you two. There is a FB page with many recipes, I think it's called the Acidwatchers Diet Warriors Group. Dr. Jamie Koufman has a lot of free info on her web site. Dr. Jonathan Aviv has a lot of info scattered about the internet. Maybe also look into vagus nerve damage as causing the coughing?