Can someone explain the gravy separator for me? I do not do gravy and don't have this tool. However, my SIL bought one a couple of years ago and just got it out to use it and says she doesn't know for sure how to use it. I don't have it, have not seen one, and she lives in TN so I can't check hers out. She thought the grease would come to the top and pour off, but something about it not separating? Doesn't it have to sit and cool off to separate? Maybe she isn't waiting long enough? Maybe I need to buy one just to understand how it works!!