Sooooooo how do you do a fireball: we use cornstarch, stuff it in our mouth (it is very gross, try not to breath it in and it has made my friends vomit before) but then you breathe it out evenly and forcefully on an open flame, which can be tricky because you may blow out the flame.
I prefer using lots of matches. I can have my friend who taught me explain the science more as she taught chemistry. It is good to keep some water handy to rinse out your mouth. It is fun and a good party trick. That little (rough) video was the first time my kids saw me breath fire as I do worry about inspiring them to play with matches. We used it as a chance to teach fire safety.
We did do it for phil&teds! Maybe some fire balls in the staff parking lot would help with the work mania? It is very fun at parties.