Went through a few grinders trying to get the finest grind I could. Without getting to expensive I found the Krups F203 worked the best for 20 bucks or less. Better than many that cost 2 or 3 times that much. Cleaning by powdering dry uncooked rice picks up remnants and absorbs the left over oils. Then just wipe it out with a damp paper towel.
P.S. Grinding cloves will cause many grinders with clear plastic cups to turn cloudy, but will not harm the grinder. Something in the clove oil reacts with the clear plastic.