Preventing the gas when Hydrogen peroxide is added to a detergent
While hydrogen peroxide is fairly stable if pure in water solution, it can quickly break down to water plus oxygen in the presence of a catalyst such as transition metal ions--probably what is causing the gas evolution you observe. One approach you might try is to test other types of detergent - perhaps you can find one that does not catalyze breakdown of peroxide. Liquid facial soap or glycerine soap--or even dishwashing liquid--might be worth a try.

Another approach would be to mix the peroxide in right before use rather than try to store the mixture--the more dilute, the better.