From DEEP DARK in the past recesses of my memory, I vaguely recalliing the story of some beauty queen of the silver screen of yore, had a heart attack that was attributed to a long soak "in salts." (Epsom?, I'm not sure...it was DECADES ago.)
I never trust info promulgated by any trade "council" because the hyperboles fly too easy: "cures the plague, slays the dragon, ends world hunger" kinda thing!
I have tried epsom salts soaking to ease joint pain. A warm soak is always nice but I doubt it ever did much for the pain.
I KNOW a warm or hot bath will lower BP by causing a large dilation of the skin's arterioles to try to expel body heat...and it DOES feel good, but, alas, at 6'2" I don't fit into my bath tub and my gym's hot tub is being rebuilt!