I bought 10 surface rusted Lyman and H&G molds at a flea market for $250. In the past I have used "Evaporust" and "Metal Rescue" to clean my used rusty molds with varying degrees of success. I recently used an internet recipe of vinegar and salt to clean up some steel Harley parts with excellent results. The recipe is 1 gallon of vinegar and 1 cup of salt left for 12 hours. Follow with a dunk in a pint of water with 2 tablespoons of baking soda stirred in to neutralize the vinegar/salt. Finish with a very hot tap water rinse and blow dry followed by oiling with Mobil One. Has anyone used this method? I don't want to etch or damage the mold cavities as the Lyman mold steel is fairly soft.