Aging wood using vinegar and wire wool.

[TheGreek]

https://www.diypete.com/how-to-make-steel-wool-and-vinegar-stain/

[Hellzero]

Ammonia has the same aging effect on wood without using steel wool. 😉

[PlungerModerno]

I had heard about aging using vinegar and iron, and different mixes of things, some off the shelf, but this was new to me: (heads up, it's pretty unpleasant!) https://www.highlandwoodworking.com/finishing/aging-hardwoods-with-uric-acid-and-ammonia-wood-finishing-tip.html

 

 

https://fancythatantiques.com/diy-tips/diy-aging-wood/ says put wood in a bag with ammonia for a week. Sounds like the vinegar & iron mix is a much quicker way, but it depends what you're after.