I fully concur with Andrews (Fontys) reply to your post.
The only time that Shelton agreed to an enema was in cases of chronic constipation prior to the commencement of a fast. His experience, and that of all other Hygienists, is that they are superfluous, enervating and debilitating to the fasting individual.
What he described as a thoroughly pernicious practice: which I also fully agree with.