I use the Berg kit with the bleach double or quadruple diluted. I also dilute the toner a lot and replace it as needed. I usually consider the first print unusable and just a 'seasoning' of the bath. If you over-bleach, rinse the print for a minute or so, and redevelop it. I often lightly bleach, sepia, then selenium just to punch up the blacks and increase the contrast again.