Whenever I pull pork I separate as much of the fat that I can. I put it in a cast iron put (Dutch oven) over low heat and render the fat out of it. I take what's left and press it between a couple pieces of paper towel to get as much of the lard out of it as I can. (I save lard too.
) A little salt on that and it makes a great snack as long as it's warm enough so that the lard does not solidify.
It's probably not good for me but it sure is good. Takes me back to my childhood when my mom and grandmother used to render lard.
I'm not sure if that's what you mean by crackling.