I kinda understand what this is but not really. I thought it was to put in the litter so that it controls the smell and drys it out but i also read on another post that they said they used it for their liter no their food. what would you need it in food for? Also, it seems like this is hard to get and to get the right kind. Could someone tell me if this is a neccesity and how to go about getting the right kind and from where? Thank you so much. Boy, am i gedtting myself confused.