Congratulations on a great flush! Magnesium is a muscle relaxant and sleep aid, so it sounds like your body loved the extra magnesium that was in your system last night, hence your deep sleep.
It is very important to get all the waste from the liver and gall bladder out of your body, so the morning dose of Epsom Salts is very important. An enema is a great way to help ensure the clearing out of waste from the flush, though it will only reach so far. I would also suggest drinking a P and B shake or eating a couple of apples - the pectin in the apples can absorb waste as it passed through your system.