I use the oven cleaner all the time and it DOES work. Don't use the lemon scented stuff. I tried it and it does not work. I use original strength "Easy Off" brand oven cleaner. I just did some AN fittings yesterday. Wear rubber gloves. Apply oven cleaner and let it sit for a couple of minutes. I use a paint brush to evenly remove the finish. Then rinse quickly with water or the aluminum will start to turn black.