Soaking the foot in warm water that is not too hot will increase blood flow to the area bringing more of the body's own healing elements to the area being soaked. So, the increase in local temperature is what helps heal any damage, not the bath salts.
A word of warning. Individuals with compromised circulation, especially patients with diabetes, must be vigilant about water temperature. Individuals with decreased circulation will burn at a lower temperature than patients with normal circulation.
Rod Tomczak, MD, DPM, EdD