Iron Sulfate, granular Mg & Mn plus Ammonium Sulfate will really turn a lawn dark green. BUT IT ALSO STAINS ANYTHING IT TOUCHES. Plus as Ted said it is hard on Pumps, hoses, and Guns etc. Granular/powdered Fe, Mg & Mn are metals that act like a sand blaster on the inside of your pump. Unless you have your spray technic down to a perfect science, Over spray can cost you the Farm.
My point being, It is a lot safer to pay a little extra and use NON STAINING products of FE, Mg & Mn.
BTW Feature 6-0-0 is low staining/non staining.
it is one thing to do a off label applications. It is total stupidity to post it on the world wide web and expect people to approve.
You can lead a Donkey to water but you can't make the Jackass Drink