They work pretty well
I used these a lot when I was a kid and I remember them being a lot worse, but they still stink pretty bad.  I recommend using them in a small room.  that concentrates it much better.  I broke 3 in our small break room and about killed my co workers, lol.  I broke 1 in a pretty big room and it still ran my friend out of there, it just dissipated more quickly.
Rating: 4 stars