I don't know about you guys,....but when I was driving, I insisted on a spotlessly clean interior,.......and I would polish all my glassy surfaces with Windex, or some sort of Ammonia-based chemical compound.........
But,....I would NEVER use a Big Smear of Vaseline on,....say,...like a PDA surface,...or a...lens,.....That would produce a blurry, indistinct image, that would be impossible to...see anything through clearly,...maybe even to the point of barely being able to ...identify the color of the jacket the driver is wearing.......
That would be Terrible,.....and Not a Very Good Idea for cleaning any glassy surface,....although it does make a Dashboard shine just as well as ArmorAll.....
No,....I would never Recommend that........