It's not likely that you have access to anything needing lubrication from the bottom.
The bottom pivots for the curtain rollers may be visible/accessible but anything else on the bottom
would need just a tiny dab of the correct grease.
The oils used are typically clock oils anything heavier will mess it up.
Cool. Thank you for the info!
"If it can be written or thought, it can be filmed." - Stanley Kubrick