The salt that many of us use around here and in my experience is the mellowest of all actually comes from Europe. France to be exact. Here it is named Celtic Sea Salt and it's a light grey color and it's a little moist. You might try and look for any French salt and it should say "Sal de Mer" which actually translates to Sea Salt. The give away is that it will be a light grey in color.
Another favorite around here also does not come from the USA but it is mined in the Himalayas. Lastly the other favorite that is also a mined salt that one is from the US and the brand is Redmonds and it has a slightly pinkish color I believe the Himalayan is also pinkish. The important thing is that the salt is pure and must not contain iodine or any anti-caking agents.
A very common mistake around here is people using 2 tablespoons instead of 2 teaspoons per quart (liter) It also helps the SWF both in taste and effect to make it lukewarm.
To me it's hard to believe all the whining that goes on and on here about the SWF. I drink the whole quart in 15 seconds badaboom badabim and I hardly taste the salt at all.