Consider a whitening schedule: initial daily sessions up until desired shade
https://privatebin.net/?f9b876f2964277b1#7aMW9L5zTRzG9ZoxV4V2mgKCwwKKNxwiYbNVfNxrSWVe
Think about a whitening schedule: initial day-to-day sessions till desired shade, then weekly or month-to-month touch-ups to keep brightness without over-bleaching.