Here is a copy of a message on peroxide baths:
The reason people buy the concentrated 35% food-grade peroxide is because it is more convenient for using it in the bathtub (only 8oz per bath vs. 4 big quart-sized bottles of 3% peroxide per bath) and doesn't have any chemical stabalizers added (like the 3% drugstore peroxide has.)
And Ali, I would work up to 4 bottles, start with one and go up. (Depends on the size of your tub too.)
I was told for a detox bath you should shut your eyes and pinch your nose and submerge as long as you can hold your breath.
Let us know how it works.