you sit , or lay inside the pyramid in the dead center.
the shape of the pyramid gathers energy from the grid point on which the pyramid is situated and "locked in".

After a lil bit.. you have a psychedelic experience of sorts.
It was used to raise consciousness , heal , even develop certain abilities.

David wilcock talks about this , and mentions an initiation process in which the person in the pyramid meets his shadow self.
There are several outcomes , and as he says , one guy turned out to be pretty evil when he came out.
He started some shit, and then he ran away.
They sent a whole army after him.

He was standing on a hill top and just pointed his finger towards them until they all died.
Then , he carried on to reanimate their dead bodies , and make them dispose of themselves in the river.