Aircon Vent Flaps - Lubricate?

[dr. d]

What do you all use to lubricate the flaps that control the direction of the aircon vents?

Matigas na yung sa amin, halos 10 years na kasi yung kotse...

Kailangan bang ibaklas yung panel?

i am wary of putting petroleum lubricant there.. baka lumambot ang plastic.. at sobrang lumuwag.
i imagine, dumi lang yan.. how about plain water mixed with a little rubbing alcohol, 50-50 mixture siguro?