So is the hydrogen peroxide still usable to whiten something else after it's been used once? It sounds like if it breaks down after a week (during which was probably used to whiten anyway), you could probably just dump it in your back yard.
I did a marathon bleaching session once. I used 5 bottles of peroxide and a fish tank.
I bleached 5 Commodore 64 1541 floppy drives, two C64s themselves, a 1581, and a mouse.
All with the same fishtank full of liquid, out in my driveway.
When I was done, I just dumped the peroxide all over a group of kids walking by.
Just kidding. I dumped it on the ground and blasted it with the hose and let it dry.