Dr.Clark's is one of many flushes. There is not one right way. If you read under cleanses at the top of the page, you will see there are many different cleanses.
I tried several and I finally settled for the one that I can eat the berries and heavy cream at 7 pm I think it is #4.
I was always so hungry that I kept cheating.
Another one is Julia Chang's, sensible health.com. Very educational reading.
You might get confused with all the different methods, so just do the one you feel comfortable with. Just don't get uptight about it, relax.