Since the person won’t be getting the item back, try to find something small that they won’t miss. A hairpin, pencil, eraser or another school supply item might be a good choice. Since the item is going to end up in a stream or river, try to choose something that isn’t going to pollute the water. A small piece of paper or cloth will eventually break down, a bit plastic object won’t.
For the spell that completes the above chant, light a red candle or a white one. You do not need both; the red candle is preferable if you have it.