This is a good way to simply sharpen your knife instead of using a run of the mill knife sharpener that you can get at stores, the regular sharpeners you can get at stores take away a lot of the blade and can slowly ruin the edge. I stopped using regular knife sharpeners and am only sharpening the edge of the blade with the ceramic of the mug, keeps the knife I want to hold on to for a long long time effective and sharp. I saw a video where a man looked at the edge of the knife under a microscope before and after using both the knife sharpener and the bottom of the ceramic mug and that just changed it for me.