If water should not be used to stop Cerium fires, then what can you use to stop it?

Question

Background Inforation:

Cerium is a strong reducing agent and ignites spontaneously in air at 65 to 80 °C (150 to 175 °F). Fumes from cerium fires are toxic. Water should not be used to stop cerium fires, as cerium reacts with water to produce hydrogen gas.

Answer 1

Baking soda is a carbonate, and active metals can reduce these to carbon.

Cerium fires are rare occurrences, but procedures for fighting other fires involving reactive metals should be applicable.  In WWII, Germany dropped magnesium firebombs on London.  Magnesium reacts violently with water and CO2 when burning.  I think the only somewhat effective solution found was to smother them with sand, but they were notorious for being difficult to extinguish.

It appears that a Class D Fire Extinguisher is effective on such fires.

The wikipedia article on sodium lists some fire extinguishers that may be effective - one approach is to use an inert salt (such as NaCl) mixed with a plastic that melts to smother the metal and cut it off from oxygen.

Answer 2

would baking soda be a viable solution?

or if it is small enough could the flames be smothered?