Not true. You can easily cleanse the entire colon with colemas. You will notice that when during the colema the water reaches the beginning of the ascending colon. With a little practice, you will figure this out in no time.
If you want to do the liver flush now, at least do a water enema on the day of the flush (day 6) and two consecutive enemas after about 2 days following the flush.
Once the colema arrives, do one of those. This should work for you.