Have a mold in 32 caliber that I use for my Pardini 32 ACP. All is well as far as accuracy. [Perfect]. There seems to be a carbon build up in the vent grooves of the mold that will not dissolve . Tried liquor thinner acetone mineral spirits. I can get it out with my finger nail but it’s a bear. Any folks on here that would have any suggestions This mold works to well to mess it up