I learned something about staining the cheap Eastern White Cedar shakes I got at Home Depot. The stain is supposed to age the wood and give it a gray and reddish look. The procedure I found for making the stain is to put steel wool in vinegar (white, although cider vinegar will work) and let it rust for a day or two. Well after a week the steel wool had barely rusted. Then I figured out to just wet the steel wool with water, and vinegar, then let it sit outside the liquid. Here is what it looked like barely rusted after days in vinegar. The only parts that rusted we’re sticking out of the vinegar.

And here it is just hours after wetting it and setting it out.

Then I simply add it back to the vinegar. I also add some black tea bags. The combination of these affects the tannins in the wood. Here are some before and after.

It only takes a few minutes to age. Really looks nice and rustic, like an old barn.
Here are some on the roof.

So if you find instructions online to age wood be sure not to leave the steel wool in the liquid. Get it wet and then leave it out.
And the tea bags help to give a little redder tint while just the steel wool will be more gray.