I think otto meant alfalfa meal, as in this:
alfalfa meal
Thats the specific name of the pellets they make. I know them because I have used them on and off. I currently have their Desert Blend for mine, which is basically ground walnut shells, which is not very popular but I like it. My brother who's used the walnut shells for a white says its good to keep/create heat. I find it easy to clean. Im not attracted to tile because of how cold it is [I dont like belly heat either because I fear it burns.]. Just my two cents.