Iron Skillet

Had my trusty iron skillet for years and years - better than any non stick pan I could buy. I rarely have to use more than a scant tsp of oil/butter to do eggs, pancakes, veggies or just about anything. When finished cooking while still hot, I've always poured in a layer of Kosher salt and rubbed out. I don't oil it again as it could go rancid.

My question is after reading so much about food-borne illness,etc., is this a safe practice? We've never been sick but am curious of opinions.