1) go to a place where you don't speak the language.
2) make sure that the only people who come to you for healing have an invisible disability.
3) make sure you have a translator who has prepped the community for your visit.
And if it were confirmed and subsequently broadcasted as true, it would only serves to encourage more people to do phony faith healing activities.
It takes many years of immersion and language study to really understand what is going on around you.
This is a campaign, and it is highly numbers-focused. The less you know, the easier it is to report great numbers for donors in America.