Dan's honing oil is recommended to be used with your sharpening stones during and after sharpening. Small metal shavings are made when you sharpen your blade and these can clog the pores in your stone. Dan's honing oil is a light mineral oil that helps keep your stone's pores from getting clogged. The oil is necessary to maintain the effectiveness of your stone. In addition, it is a good all purpose lubricant for many of your household needs.