I bought some Purple Power and a soft wire brush and got to work... Mine came clean really easy but their was still some spots I couldn't get and the wire brush didn't scratch it at all! But it wasn't a hard wire brush, then my buddy gave me some fine sand paper and I sanded it down by hand and recleaned it with Purple Power then painted it! When I sanded it, those spots that didn't come off with the wire brush came right off.