As promised in my previous entry, I bought some magnesium citrate today after reading that it had comparable oil-absorbing effects to Milk of Magnesia without the annoying white, chalky appearance. I applied the magnesium citrate to just the right side of my nose for easier comparison and left it on for 3 hours.
Right away I saw one drawback in magnesium citrate as compared to Milk of Magnesia, which is that it has no mattifying effect. In fact, magnesium citrate itself has a slightly shiny appearance, whereas MoM almost immediately reduces the appearance of shine as soon as it's applied to the skin.
I left the magnesium citrate on for 3 hours while being very careful not to rub or blot any oil off my nose. Unfortunately, when it came time to blot the oil off my nose and compare, the right side of the blotting sheet appeared only slightly less oily than the left side. The magnesium citrate reduced my oil by maybe 20%, which is something but not reason enough to keep using the stuff.