Got this info out of Field and Stream. Combine calcium phosphate and sodium chloride (mixing salt in a 1:1 ratio.) Can get both at a feed and seed store. This is much cheaper than buying commercial products and will work just as good. Clear 3x3 area out and dig out about a foot deep. Poor in most of the minerals and mix it with dirt. Sprinkle the rest of the minerals on top. I tried it this year and there is a hole big enough to swim in. That is if we get any rain.. Good Luck!
"Its common since to take a method and try it. If it fails admit it frankly and try another.
But above all try something."
Franklin D. Roosevelt