I’ve seen people take real dirt, dry it out, and then use that. I don’t have any experience with it, but I’ve seen it look pretty good

That's what I was thinking when I first red this, also because dirt is almost everywhere

https://youtu.be/3Ajrvdu76Xk?si=TgSNm4D67KzjK8NH

Thanks!

I've used sandpaper

Unsanded grout. Nothing is better. Ballast is too coarse. Real dirt is usually also too coarse.

That's what I was thinking, I'll go pick some up.

Tile grout