On this forum swamp cooler seems to mean anything that involves a tub with water.
In its simplest form, its a wet tshirt with the tail in the water. Fan optional.
Doesnt do anything at all, plus its kinda gross. It might work in the desert, damn sure doesnt work in Texas.
Next, and far more common is a tub cooled with water frozen water bottles. Definitely works, but the temperature regulation depends on you adding ice at regular intervals. This works well if youre home a lot.
This is the point where most people break down and get a fridge or freezer and a controller.
OR, if youre in a tiny apartment brewing in the laundry closet, you could do what I did. Immersion chillers, submersible pumps and ice water. I can throw enough water bottles at it to last 12 hours and control the temperature to well within one degree Fahrenheit.