I admit to not reading all of this thread so if this has been said - sorry. Do rust blue, easy and more durable than hot blue. All you need is a box with a light bulb for a bit of heat and a dish of water for humidity. Laurel Forge works well and is not a disaster if you touch it with bare hands. You also need a SS brush from Brownells and a piece of abs pipe cut open to pour boiling water on the parts to turn them blue. (easier than it sounds)