Take 1 cup shredded Ivory soap
Boil 1/4c water. Add shredded soap a Tablespoon at a time. Mix until melted
Add food coloring.
Press mix into tins, ice cube trays, or cookie cutters.
Now, I have read there are different ways to do this... you can microwave it for 10-15 minutes. But since I was using tin, I cooked them on the lowest heat my over would go for about 30 minutes. I have now learned you can also pop these in the freezer for 30 minutes.
Let them dry for a day or so in the molds.. pop out of the molds and continue drying for about a week. Enjoy your bath crayons!