Yes, on the bag of Epsom salts I have, it says that as well. 1/2 Cup to a quart of water would probably be about right. For myself, I would never use that much. I also do not take baths (I shower) and I have not had to apply soaked cloths with it.

I get crampy feet from the water if it's too warm not from the Epsom Salts. If the water is really lukewarm, it will take away any crampiness in my feet that I might have. Everyone is different even those with CMT. Some like it really warm and it works for them. But not for me.