Massage oil spilled on iPhone - large dark spot on front screen

Hi all,

A bottle of massage oil spilled on my iphone, and now there is a large dark spot in the front. At first it was in the far upper right, but now it's maybe 20% lower. If I tilt it and look at it horizontally from the bottom, I see the oil covers maybe 60% of screen and looks like a coral reef. The screen also kind of looks like a diagonal checker board, with these defined lines criss crossing the screen.

Fortunately the phone is 100% functional - touch works, sound works, etc.

I've tried using a vacuum by the openings, and I got a fair amount of oil out but the big spot barely changed.

What can I try now? I don't feel comfortable dis assembling it (given that it works well).