Roughly chop the jewelweed leaves until you have enough to fill a mason jar almost to the top. Make sure the leaves are packed down.
Cover the leaves with olive oil (or any neutral oil you've chosen).
Fill a saucepan or slow cooker with 1 inch of water. Carefully place the jewelweed- and oil-filled jar on a trivet in a double boiler or in the slow cooker.
Slowly heat the water until it reaches 110 to 120 degrees. Turn off the heat.
Over the next 24 to 48 hours, infuse the oil over very low heat by bringing the water back up to temperature periodically over the next 24 to 48 hours. Don't leave the heat on for any prolonged amount of time and never allow the water line to get too low.
Once the oil is infused to your liking, strain the jewelweed leaves from the oil.
Pour the infused oil into a heatproof bowl (or double boiler) over simmering water.
Carefully add the beeswax to the warm oil, stirring until smooth.
Pour the finished salve into small tins or glass jars.
Let the salve cool for at least 30 minutes before using.