You do not need to clean or rinse the containers before sending to TerraCycle, but please try to remove as much remaining product as possible to ensure your items are dry. TerraCycle also encourages you to ship your box when it is full of items to minimize the transportation carbon footprint. TIP: Collect empties from friends and family who also use our products, then ship them back in the same box. It’s another way to minimize the carbon footprint.