One of my old friends is a street performer. The show was mostly comedy, trying to gather a decent crowd around. When there were enough he would do the main attraction which is to swallow a sword.

He would always get a kid from the audience to hold the sword for him and then after the trick he would get the crowd to agree on what a great performer the kid has been and gave him $5. This was the way to get most people to open their wallets and pay v4v for the performance.