My son wanted to make homemade crayons for his classmates for Valentine’s Day. We melted broken crayons in a plastic container in the microwave. Then we poured the melted crayon into small metal cookie cutters my mom had given us (this requires adult supervision, as the melted crayon is very hot). The cookie cutters were sitting on top of a silicon mat. The crayon that drips onto the mat just washes right off when done.
It took us about 1 hour to make 24 crayons for his classmates. It was a fun project and free!
My daughter did this with a gallon bucket of old crayons. She didn’t tell me and the container she used was too small. Wax got all over microwave! Had to toss the microwave, but got some pretty neat colors from the crayons.