It's not the concentration, it's the amount. By that logic, a single spray of air freshener will have the same effect as emptying the entire can in a room, because they're the same concentration. And I very seriously doubt you're using 7g of bleach at a time to clean with, regardless of what it's diluted to, so I really don't understand what your goal is here?I can honestly say I’ve never tried to clean a bathroom with <300 ppm chlorine. I have cleaned it with >500ppm over a lot more surface area.