Take used wet ones and rub on freshly sanded raw wood. Van also do with tea. Once it dries, coat with a varnish or poly.
Here is an article that may be of interest: https://www.familyhandyman.com/woodworking/staining-wood/how-to-stain-unfinished-wood-with-used-coffee-grounds/ I hope this helps!
I believe these videos will help you out. Best wishes!
Soak in hot water, spread on, wipe off!!! Over and over till desired shade.