The Tao, NH3 and HCl react to form NH4Cl, which is a fertilizer (commonly called "sal ammoniac"). Also, I thought Cl2 was used in World War I, not II.
coboled, both ammonia and chlorine are gasses, so you can't mix them in a oven pan. Also, chlorine is more dense than air, so it would permeate to the lower levels. Ammonia is less dense, but is flammable in a specific concentration in air.