1) I recall Amy standing in front of the group in a darling apron. Holding a recipe card. She took a piece of coal (could be a simple rock painted black) and placed it in a frying pan. She asked the young women how long it would take her to turn that piece of coal into a diamond. I believe this is when she pulled out the blow torch. She didn't use it of course. Just a visual aid. 🙂 After some discussion, she bridged over to what it takes to be perfected in Him.
2) Another idea would be to use a tarnished piece of silver and polish it while explaining how our Savior helps refine us - in the end the silver will shine.
Jenny says: If you are teaching a class of small children, you could let students shine the silver. Here's the original video referenced, but the quality is very poor: