Almost no matter how you do it, it’s going to be a horrible waste of good drinking water to try to extract cooling from the temperature of the water. If you are in a dry climate, make a DIY swamp cooler. Otherwise shell out for a small AC unit.
Also; using your free lease-included water for stuff like that, is probably the quickest way to no longer have water included in your lease…
The link you decided not to follow gives a lot of context. Although in French, which I do not speak.
These people weren’t murdered at Dachau. They are being cremated there, after dieing aboard the prisoner transport train from the Royallieu-Compiègne internment camp.
The German Wikipedia about the Sonderkommando photographs describes those as the only surviving photos taken by prisoners inside the camps.