I've seen these fans and Yes, they do work, but they really don't move
much air at all, I'd guess they move 1/20th the air volume of a
"normal" fan. A $15 box fan pointing at your stove would do a much
better job of circulating air. But again, they don't need any
electricity.

If your goal is to move a little air when there is no electricity, then
this fan will do that. If your goal is to circulate the air in a room,
this will not help much.

Maybe call some stores in your area that sell wood stoves, they may
have some you could see in action. Good luck.