.Dump some ice cubes in and run it until they're all minced up.  They sharpen the blades.  While you're at it, any time you eat/use any sort of citrus, throw the leftovers into the disposal instead of throwing them away.  Keeps things fresh! And while citrus will not cut grease build up, vinegar will ...   Trust me, "Lula" has never had a stinky sink!   www.lulasforlunch.com