I bought this along with an anti barking collar and have been able to sleep through the night ever since, with my 14 week old puppy. I only switch this on when I am either going out, or at night,and it seems to do the trick. I cant smell anything, but have it plugged in just above her bed (she cant get to it) although on the first day I plugged it in, she growled at it, which I thought was hilarious.