How To Remove Black Walnut Stains From Skin And Clothes. Green walnut stains are very hard to remove from your skin, not to mention clothes. If, unfortunately, stained your hands with green walnuts, your skin will become dark brown to black, and you will get rid of this problem over time.Click to see full answer. Besides, how do you get black walnut stains off skin?Mix one tablespoon of baking soda with one-fourth cup of dish detergent in a shallow bowl. Use the old toothbrush to apply this mixture to your hands. Scrub the stain with the toothbrush using the same circular motions from step 4. Continue scrubbing until the stain has begun to go away.One may also ask, how long do walnut stains last on skin? If you’ve ever picked up walnuts off the ground or handled walnut wood during woodworking projects, you’ve found that you quickly acquire a yellow stain on your hands. If left untreated, the stain can hang around for days. It will eventually wear away on its own, but you probably won’t Similarly one may ask, do black walnuts stain? Black walnuts can create quite a mess if they’re left to lay in your yard or driveway. If left to lay, the evidence they leave behind takes a while to fade. On the other hand, they can be quite useful when used to create a natural homemade wood stain.How do you get walnut stain off your hands? Wash your hands thoroughly, using a good quality soap and warm water. This will help remove any residue that may be adding to the stain. Apply lemon juice. You can squeeze the juice of one lemon or use roughly a half-cup of commercial lemon juice. Follow up with a round of cooking oil. Wash up.