Looks like the magnets pull the other metal impurities out of solution. I get the smooth flavor too by using expensive ultra pure Iodine crystals and potassium iodide. The grade that is used by analytical chemists that needs to show up insanely pure for expensive analysis. Food grade/usp/pharmecutical grade is way behind this stuff. I am guessing it is other metals in the less pure Lugol's that gives it the harsh taste. I sell mine here.