I have been wondering about these magnesium references and their differences in the different flush directions too. I have purchased magnesium oxide because a natural health-care practitioner suggested to put two next to my bed during the flush in case I felt there was a stone stuck. I never had to do it but I have used it when my gall bladder felt tight at other times between flushes and it worked great and relieved a headache too.
I have just purchased a bottle of magnesium citrate that says on the bottle that it is a "highly absorbable diatary supplement. It is by Solgar and says two tablets daily at mealtime as a supplement for the essential mineral magnesium.
The interesting thing to me is when I was reading about the cause of gall stones one article suggested that it was from not having enough magnesium to balance the calcium present and thus the calcium would bind to the cholestrol to form stones. Have you heard this? This would make sense that I have been low on magnesium because I have had a history of heart palpitations. I have read that gall bladder trouble is often associated with the heart thing, but perhaps the whole thing is a matter of magnesium.