Everything I do was by accident or just plain experimentation. One dose doesn't do one thing and the next dose does something else. It will affect the entire body all at once. One dose may very well be enough. I am looking at my container of Epsom Salts . It says, as a laxative, 1-2 teaspoons in a half a cup of water. Repeat if necessary in 4 hours . Limit of 2 doses per day. Lemon juice may be added to improve taste.
I'm sure you can find rationale for one big dose or 2 half doses. Try it the way you want to do it and just make note of the results.
By the way in off weeks of LF, I do CE's. I take one dose of ES 1-2 hours beforehand.