The question asks about "stain using black walnut leaves". It is not the leaves, it is the hulls of the nut that contain the staining substance. Note that the recipe below is for a dye for baskets. I suspect that the dye prepared with minimal water would be most suitable for staining skin.
From http://basketmakers.com/topics/ht/htwalnutdye.htm:
How to Make Basket Dye From Walnut Hulls
By Susi Nuss
Walnut hulls can be used in this simple nature craft to create a dye for coloring your baskets a warm brown. This dye can be used on reed baskets and some types of woodsplint baskets. Follow these simple instructions.
Difficulty Level: Average Time Required: 30 minutes
Here's How:
Tips:
The colour of a walnut floor will actually depend on the stain which used on it. Some ways to describe the colour of a walnut floor with different stains would be light brown, medium brown, chocolate or coffee coloured.
It depends on the specific shades of black and brown stains you are working with. To achieve a desired dark brown color, you would need to experiment with different ratios. Start by adding a small amount of brown stain to a small portion of the black stain and mix well. Adjust the ratio by adding more brown stain if it is not dark enough, or more black stain if it is too dark. Once you achieve the desired shade, use the same ratio to mix the remaining 5 gallons of black stain.
The most popular natural wood stain color for furniture is a medium to dark brown, such as walnut or mahogany.
Wash with soap and water
An ounce of English walnut nutmeat contains 4.33 grams of protein.An ounce of black walnut nutmeats is 6.82 grams of protein.Black walnuts also have nicer flavor, but it's hard to separate nutmeats from shell, and it's nearly impossible to get rid of the stain from handling unhusked black walnuts.
The available wood stain colors for this project are: natural, oak, cherry, mahogany, walnut, and ebony.
wd 40 is a miracle worker it willl work
The available mantel stain colors for customization include options such as mahogany, oak, cherry, walnut, and ebony.
To achieve a rich and even finish when applying walnut stain on oak, it is best to sand the wood thoroughly, apply a wood conditioner, apply the stain evenly with a brush or cloth, and wipe off any excess stain. Allow the stain to dry completely before applying a clear finish for added protection and shine.
Get walnuts and mash them up with liquid varnish and then paint
You can't, it is a tissue stain. However, as your skin replaces itself you will find that in time the stain disappears. In about a week you will be fine.
stock is standard american walnut, no stain.