I think that to find out if this method works for you you would need to collect your stools in a container and look for stones. It would also depend on whether or not your bile system is clogged with stones, sludge and parasites. If it is clogged then it may be necessary to soften or dissolve the stones, break up the sludge and kill the parasites. With H. Clark's method a person has a better chance of pushing out stones and sludge, partially clearing out the blockage and with each Liver-Flush more of the impediments are cleared out.
H. Clark advised doing the Liver-Flush in the evening because it fits better with the way the body shifts functions over the course of a 24 hour period. Some people have reported that they do them at different times because it works better with their schedules, especially people who's natural cycle is to sleep during the day.
Are you doing this because you think it is a good idea for good health or because you have some problems that you want to cure?