Novelty, in my option. Can't say it won't put out a fire. But at the cost, lack of user control, and not knowing how messy or destructive it is to non-incinerated components, I'll buy a hand held one for approx $15. Or 6 for a total of their blueball (ball blue) retail price.
According to their website heat will not trigger the device, only open flame. However the website also says, prolonged exposure over 200F destroys the device so I think you can't use it under our hoods.