I think we can assume that most cults do not start with the intention of becoming a cult. Cults are a deformation of a belief otherwise held to be orthodox. The real question we need to ask ourselves and for which we need to pray is this: if we can learn how they start, can we prevent them from ever starting?
Any discussion of cults in China cannot fail to mention the most serious cult in Chinese history: the Taiping Heavenly Kingdom (or Taiping Rebellion). From 1851 to 1864, Hong Xiuquan, believing himself to be God's second son using a Christian tract to interpret his dreams, started a rebellion to destroy demons (interpreted as the ruling Manchurian government) and install his heavenly kingdom. The Taipings took Nanjing and held much of south and central China. The rebellion killed around 20 million people, with some estimates as high as 40 to 50 million.
Even though 150 years have passed, the Chinese government, especially the current government has not forgotten. The Taiping rebellion was a cult gone bad, and the current government has no desire to see a cult reach such disastrous proportions again.
There are many lessons to learn before we can answer our primary questions of how cults start and if we can prevent them. It is not always the same, of course, but interestingly, the Taiping Rebellion started from dreams that Hong Xiuquan interpreted through a Christian tract. Do tracts start cults? No.
What does? A lack of truth. Thankfully, rebellions are not a common product of a lack of truth. Weak believers and dead churches are frightfully common, though. The Dong people do not need tracts or more shallow teaching. The Dong people need the truth of the Gospel.
Lord Jesus, you are the author and sustainer of all things. You are the foundation of your Church. You are exactly what the Dong people need, and we want to do everything possible to let them know you. Cults bend your truth, and we want to keep from anything that would encourage a cult, but we need your wisdom to know how to share your Gospel, especially with language and culture barriers that can easily skew your message. Teach us, Jesus.