I add a 9mm case full of Hex boron nitride powder to an ounce of Kroil. I get a difficult aluminum mold up to casting temp and apply the kroil tothe cavities with a Q-tip then cool. I repeat this two or three times and the mold starts releasing bullets like they were spring loaded.
After several hundred bullets, i repeat treatment. It has given new life to old molds which were sticky in the past.
I have not yet tried this on Iron molds.
Careful handling HBN, particles are smaller than pores in your skin.