We used to sell Cold Fire when we were in business. Absolutely fantastic/safe fire fighting material. It used to be the only approved fire extinguisher in Indy car racing pits and was used extensively in NHRA classes. I used to work at NHRA tracks and witnessed first hand how it quickly put out nitromethane fires.
Amazon sell both the 13 oz spray can and the concentrate.
I am not a huge fan of the spray cans. The best extinguisher would be a 1.5 or 2.5 gallon water fire extinguisher with the concentrate added to distilled water. If you go that route, I have the mixing instructions.
As a side note, I did my own testing with a local fire department and we put out major tire fires with one extinguisher and even put out a magnesium fire. When I was selling, it was not rated for magnesium, but they were working on certification.
Jim