Kingham washroom door

The washroom sliding door on my Kingham is getting hard to open/close. Other than cleaning the rail it slides on is there any suitable lubricant to help is move more smoothly?

Candle wax usually works on drawer rails etc. i use it on my sliding patio doors in my property .
Boaby

hi,we use sillicon spray on ours,spray on track then buff it off till smooth.