There was once a time I didn't have air conditioning. I resorting to buying this.
I thought it was going to be a replacement air conditioner. NOPE! It's a piece of junk! The so-called "secret" of it's cooling power is that there's this filter inside the box. You fill the top with water and it spritzes the filter, keeping it cool. There's a fan in the back of the unit where the air gets cooled by the filter. The failure of this is that there is nothing keeping the filter itself cool. There's no like freezing gel that keeps it cool for hours, it's just sponges. Even if you freeze the filter before use and pour ice cold water on top and fill it with bits of ice (there's not much room), you only get 20 minutes before it becomes a standard fan.
But I found a solution to it.
Get something to put in the freezer (I used an 8 quart square container) and fill the bottom with water. Just the bottom, enough to make a thick ice block. You can fill it up to halfway as long as you have plenty of empty space. Freeze that water until it becomes a block of ice. Remove it and fill the rest with ice-cold water. Add ice cubes for extra chill.
Before using the unit, freeze the filter. When ready to use the unit, pull out the filter and get that 20 minutes of chill. Once the filter defrost and the air is now circulating, take out the filter and dip it into the ice water. Leave it there for 10 seconds. Pull it out and place it back into the unit. You now have 10 more minutes of cool air. Once that defrosts, repeat dipping it in the ice water.
This method lasted me for 6 hours, enough for the night time to come and finally cool things down enough to use my big fan. I actually bought a second filter so that I can just replace the filter immediately, but I didn't have a chance to use it because by that point, I got an air conditioner. But before I had that AC, that method worked well for me. It's not the best, but when you have nothing and the sun is murdering you, you're willing to put up with anything as long as it cools you.