Comie Marble Mortar and Pestle Set,Mushroom Shaped Pill Crusher and Spices Grinder,Manual Coffee Grinder,3.7 Inch,1/2 Cup

How is this cleaned?

Is this little set better than a heavy-duty mortar and pestle? How does it work?

Is it hard to grind spices?

Should the grooves extend throughout the mortar? Mine is smooth on the bottom, and on the bottom of the pestle. I'm not getting good results