I have used celtic salt for years. Add 1/4 tsp. to a liter of filtered water and drink through the day. I noticed that when I work hard in the yard, I avoid muscle pains if I immediately drink a glass of water with a good pinch of the salt in. Every other day I take Lugol too. For the magnesium I use the magnesium oil which one sprays on the skin. Wonderful stuff.
Did you know that Celtic sea salt has three forms of magnesium in it? And that magnesium is essential for regulating blood pressure? Mine stays at 80/120 but is now 70/110 since I walk every day.