This sounds a lot like the old timey method espoused by a doctor a number of years ago. He wrote a small book with lots of pictures of the various types of mucoid plaque that his patients had released. His case studies were extremely poorly done, however, and I think that this cost him a lot of credibility.
As I recall, his method was major lemonade fasts with at least daily bucket-type enemas. Very brutal, fasting lasting up to a month long I think. He had various plans. Pick your poison. I think it was much too harsh on the endocrine system, but apparently it worked for many of those who stuck it out.
I think that the gradual P&B shake program sounds more reasonable, except that you seem to be taking it to the extreme. Perhaps you are feeling a lot of outside pressure to make it happen quickly (work, relationships). If this pressure is mostly self-imposed, perhaps you would consider taking a slower course with more food (and less sugar, if that's an accurate comment). I'm glad that you're at least drinking milk. I hope it's full-fat. Milk actually has a fair amount of Sugar in it, BTW.