I regenerated some Purigen two days ago. After soaking in a bleach / water solution for 24 hours it looked nice and white, prior to that most of the bags were dark brown. When I started rinsing the the bleach out, the Purigen started to turn brown again. I don't think it was Purigen from the middle of the bag, but I guess it could have been. When I soaked it in bleach, I did swish it around with my hands, I also tried to mix the bag up as best as I could. Some youtube videos have the people violently shaking it up. Is it normal for Purigen to turn brown that quickly or was it probably not as clean as I thought it was?