Hydrogen peroxide has another bacterial related use. If one is unsure of the existence of pathogens they can spray peroxide on all the surfaces and just listen

Hydrogen peroxide has another bacterial related use. If one is unsure of the existence of pathogens they can spray peroxide on all the surfaces and just listen. The bacteria will bubble up making almost a hissing sound. Bacteria free surfaces will make no sound. I also found that peroxide will change the color of some bacteria making it easier to see with the bare human eye.