i have a great old cast iron skillet that has some rust pitting in it. I cleaned it up with a wire brush on the drill, and washed it thoroughly with warm soapy water. I then heated it on the stove burner, and applied a coating of crisco to it. I am currently heating it in the oven at 350 degrees for an hour. I will then allow it to cool slowly in the oven. I intend to repeat this coating and oven heating a couple of more times. Will this treatment prevent food from sticking in the pitting, or am I wasting my time?