In one sentence, describe what the following article is about:

Keep the water boiling until you’re ready to transfer it. Use a container with a wide enough opening for a paintbrush. Leave the tea bags in the container for the entire 24 hours so the mixture fully darkens. Use a 0000-grade steel wool pad for the best results. Let the steel wool soak in the apple cider vinegar for 24 hours. Make sure you cover every part of the wood’s surface that you want to darken. You want the black tea to fully absorb into the wood before you apply the next coat of stain. Paint on the mixture in the direction of the wood grain. Make sure you cover the entire surface of the wood with the mixture to prevent patches and streaks. The mixture will cause the wood to oxidize, and you should start to notice the wood turning darker.
Bring two cups (473 milliliters) of water to a boil. Pour the boiling water into a heat-resistant container. Steep two black tea bags in the container of water for 24 hours. Put a steel wool pad and 16 ounces of apple cider vinegar in a bowl. Use a paintbrush to brush the black tea onto the wood. Let the wood and black tea sit for an hour. Apply the steel wool/vinegar mixture to the wood using a paintbrush.