Grease to use on plastic runners.? Does anyone know a safe grease to use on our church assembly...

Does anyone know a safe grease to use on our church assembly room room divider doors.
The runners are made up of a very tough plastic so the grease has to be a type that will not reduce or attack it.
We would need to know how to get this contained by a big tub as there are like mad of doors.
Answers:    Try a dry lubricant like Silicone. Any grease or grease would attract dirt, and that dirt would grind and damage the plastic over time.
WD40