I'm building something out of weathering steel (A606). It is chemically formulated to rust until it becomes chemically stable and stops rusting. Its composition is: Carbon: 0.22%; Manganese: 1.25%; Sulphur: 0.04% and Copper: 0.2% (minimum).
I want to accelerate the "weathering" process rather than wait for Mother Nature to do it. What chemicals should I use?