BCN Critical XXL Autoflower

Since your trying to go for that " Super" high your going to want to wait until the trichomes turn mostly amber this will give you that couch lock effect. If anything this is the perfect time for flushing this will give the plant time to get rid of the excess nutrients in the plant and the soil and it gives the trichomes time to turn amber. Now to answer your question about the 24 hours of darkness, I've actually tried 48 hours of darkness and didn't notice a difference in anything so my personal opinion is no it's not necessary.