I started Buteyko Breathing in March 2011. I also went through some major detox symptoms when my CP crossed 20 seconds.
I had headaches, 4 bowel movements per day. But I didn't have what would be considered copper dump symptoms. But I was sure getting rid of some toxins.
My Control Pause was ~ 11 seconds, and now it is around 32 seconds.
It was up to around 36 seconds....but has dropped a little since I am going through a copper dump (as evidenced by my my recent hair analysis