I strongly advise putting off Liver Flush for now especially if you are thinking of doing the Hulda Clark method.
Several separate types of "clean up" are recommended as preparation before flushing the liver with her method. Bowel cleansing is on the list but not the only one of importance. I have done her method several times and never experienced any of the numerous horror stories from CZ posters who did her Liver-Flush despite taking shortcuts that are the kind clearly against the grain of her advice for successful LF'ing.
Your mention of longterm symptoms indicating below par regularity with eliminating waste indicates a need to do the kinds of cleansing that make up a large part of the preparations she advised people do PRIOR to doing her LF.