The idea is that ba-ha done too often can release more hidden emotions and trauma than you are able to process smoothly. You want to get all that stuff out, but not at a pace that disrupts your life. By keeping the twice a week schedule, you will have time to examine the things that come up for you, journal about them etc. I almost wonder if keeping a steady rhythm of deep work and then backing off sends a subtle message to your unconscious which will match it with controlled releases of information. Pretty cool. :)