I have. It didn't work. I am talking about the style that plugs into the outlet on the wall and is about 4" x 4" in size I would say. The technology may work in theory but in practice I have not seen an easy to use consumer device that helps.
The manuals say that your grow room must be at an exact RH, temp, and must be dialed in or it won't work. That tells me it doesn't work. Worked at a grow store and a coworker swears they work, but I have my doubts.