You are not using chlorine dioxide, you must be using sodium chlorite straight. As you have to use citric acid or HCl to make chlorine dioxide and you say you don't use citric acid .
Chlorine dioxide would never cause any harm, even the FDA has approved it for mouth wash.
What is it you are using? miracle mineral is sodium chlorite, you must mix it with an activator like citric acid to get chlorine dioxide.