A Good Meditation Leader Engages the Listener in Listening.

This means that the best topic for a meditation is nothing.

This means that the best topic for a meditation is nothing.
The best spoken meditation has no agenda, no purpose, no claim, and no point.

Osho is an example of a person who engaged the listener.
Osho embodied and lived by Emerson's idea,

"Speak what you think now in hard words, and to-morrow speak what to-morrow thinks in hard words again, though it contradict every thing you said to-day."

He loved Emerson.

From Wikipedia:

"Rajneesh's teachings, delivered through his discourses, were not presented in an academic setting, but interspersed with jokes.
The emphasis was not static but changed over time: Rajneesh revelled in paradox and contradiction, making his work difficult to summarise.
He delighted in engaging in behaviour that seemed entirely at odds with traditional images of enlightened individuals; his early lectures in particular were famous for their humour and their refusal to take anything seriously.
All such behaviour, however capricious and difficult to accept, was explained as "a technique for transformation" to push people "beyond the mind"."

Osho explained this often, saying that he had no point and that what he was teaching was causing the listener to enjoy listening to him.