Question: D.I.Y clay with cornstarch and baking soda.
Options:
Add one cup of cornstarch to 1.5 cups of baking power.    Add one cup of water to make a slurry and look till it is the right consistency.    Cool and use to mold or sculpt.
Add one cup of cornstarch to 1.5 cups of baking soda.    Add one cup of water to make a slurry and cook till it is the right consistency.    Cool and use to mold or sculpt.
Answer: Add one cup of cornstarch to 1.5 cups of baking soda.    Add one cup of water to make a slurry and cook till it is the right consistency.    Cool and use to mold or sculpt.