Magnesium Salt Baths

I just had a thought and I wonder if anyone has a reply??  For a long time I have been thinking that chronic dehydration is a big part of my MS.  I know I am chronically dehydrated, most of us are.  But I notice that when I get really dehydrated my symptoms become worse.  If I am feeling nothing and I get too dehydrated I will have paresthesia and start to tingle or vibrate in my feet or spine.  Sometimes it’s subtle and sometimes stronger.  It is said that magnesium baths, with really a lot of magnesium salt, helps with MS.  I thought it was the magnesium being absorbed but now I am wondering if also soaking in water so much with the salt is helping you retain the water and actually hydrates you.  I’m sure it’s both but I think it’s interesting.  Thoughts?