reason for 10-12 hrs being optimal?

[Spiritman]

ah ok so 12 hours will have results faster and more powerful than 16?

Remember one thing, Shannon has said this several times, listening more is not essentially better. I would stick with 10-12 hours if you're able to. I usually do about 9 hours. However, remember if you do 10 hours for stage one, then you need to try and do the same amount on the other stages.