During the reverse process, extraction (or deintercalation), ions move back out.
A positive ion and a negative ion will move together.
Two ions of the same charge will move apart.
(Of course, the ions move away in time, but this a relatively slow process compared to the avalanche generation).
Water and ions move in these cell walls via the apoplast pathway.
The ions, whose average progress is slower, move in the other direction.
We say the ions have electric potential energy, and are moving to lower their potential energy.
Their charge and discharge rate are restricted by the speed with which these ions move.
The ions move with the neutral gas making the conductivity isotropic.
Outside this the ions move through the air without creating new ions.