What exactly is that "Air-Dryr Dehumidifier" supposed to accomplish

It's really just a low-level heater. I't intended to keep air warm enough to keep water dissolved in it (is that the right term?), rather than condensing and causing surface dampness. It's intended for boats and other dank places. It certainly wouldn't reduce humidity, but it would reduce relative humidity. Probably not what's required here and wouldn't do anything useful at all.