First of all, you should never wash grease straight into your sink. Lard, which is another name for pork grease, is a very tasty cooking oil. You can put the hot grease in a glass jar and use on other dishes later. It can last up to a week if you keep it in the refrigerator. If you want to discard it, leave the hot grease in a paper bowl. Once it has cooled, it will be solid and you can throw it away without worrying that it will leak.