Home-made, all natural wood stain. Using USED coffee grounds, fine-grain steel wool and plain white vinegar. This is super simple to make, very inexpensive and the results are great! Just combine 1/2 cup used coffee grounds, 1 steel wool pad and enough vinegar to fill a 1 Ltr jar and let sit for 1-2 days. (The longer the stain soaks, the darker it will be). Apply stain with the steel wool pad that's been soaking in the jar, going with the grain.