if you think about it, if the water had enough chlorine to bleach the carpet, it would be unsafe for us to go in. Imagine what that would do to our skin. Also, if you are using chlorine, I believe when you soak, the levels should be lower. Is that not why dichlor is preffered over bromine for some??
I use bromine, and other than getting dry skin sometimes from the bromine, we have never had an issue with items being bleach. It is far to diluted to expierence these results.