There are many air displacement methods and gases specially prepared for this. Even winos should know that CO2 is bad for wine. It adds extra acidity and can spoil wine as well as developer. Use a non-CO2 gas mix. Use glass with corks, use accordion bottles, use marbles. Or, use the developer to capacity in one session and toss it.
I certainly would not have bought it if they listed the ingredients on the site. It's mind-boggling that someone would sell a product that runs exactly counter to its intended use.