I came across potassium nitrate + water being used for making things cold - https://cordis.europa.eu/article/id/36036-making-things-cold-a-history-of-science-te

I came across potassium nitrate + water being used for making things cold - https://cordis.europa.eu/article/id/36036-making-things-cold-a-history-of-science-technology-and-culture https://cordis.europa.eu/article/id/36036-making-things-cold... . Wonder if that could be used too?