Hello- the Miracle-Mineral-Supplement from Global Light is okay(see thread on Verification)
As for the magnesium sold by them,it is simly not the right stuff
Many companies buy their magnesium from Great Salt Lake area(Utah)and this "salt" contains a high percentage of Hg(mercury) etc..
Better companies buy if from Honolulu or from the Netherlands(underwater sea deposit)
However the most potent magnesium(and more costlier) comes from the Dead Sea(Israel)
It enters your skin within 10-20 seconds,leaves next to zero residues etc..