Old folk lore says that this "weed" is great for helping with poison ivy breakouts. Supposedly, you rub the weed on the affected area and it helps to dry up the issue.
Although we can't speak to the effectiveness of jewelweed itself, we CAN speak to the effectiveness of this soap. We pick our own *organic* jewelweed and infuse it over winter with our oils. In the spring, we make the soap. It is very drying. It is formulated to remove all oils from your skin so that the poison ivy oil won't adhere to the skin and cause an issue. The black streaks in the soap are activated charcoal to further absorb oils from your skin.
Our jewelweed soap will also help with current issues by drying up the affected ares. It is recommended that you use it as soon as you know you've been exposed, or use it as a general precaution after working outdoors.
Use with cold water so that your pores don't open up and allow the oils to penetrate deeper than they already are. Use just liked you'd use any other soap.