Hello Chris,
I would make sure you buy a can of air that does not spray liquid propellant with the can at the wrong angle. Costs a pound or two more, but worth it.
If you get the propellant on an LCD panel, you will never get it off completely.
I know someone who took the LCD panels completely out of a projector to clean them

.
They were lined up on the kitchen table.............
I was asked to help get it working again. You can imagine what a job it was to get the convergence anything like acceptable.
Nokia monitor test had a useful test pattern that helped.
Think he sold it on ebay..........
Good luck.
Mark.