Tis true - it was the primary reason for the fail - people stopped following it - so what I would recommend is to not tell people, it would be an easy way and a fast one, as you did. If it should be so, that the effectiveness would need all 20 exercises followed - this should be clearer from the onset. While it is not a lot of time taken absolutely - it does require a lot of faith to invest a solid half hour a day, if doing this for 9 days doesn't yield a promising result.
I was sort of hoping for the real revelations coming later - but now this remains quite doubtful.
Well - if somebody on here buys your book after all - maybe we will hear of it again.
I should have put less sting in my opening post - sorry for that.