Lifeproof iPhone 5 case rainbow effect?

So whenever I put my Lifeproof case on my iPhone 5, the screen is covered with little oily marks. This is called the "rainbow effect" or "newton rings". They're barely noticeable but very annoying. I've heard this problem is very common with Lifeproof cases and Otterboxes, so I'm assuming there's a solution to the problem… How can I make these marks go away?

I actually have had the same issue in the past and there are a few solutions to this. The reason for the rainbow effect is usually because of oil. So to remove the oil, you can try cleaning it with one of the following solutions:

•Water and vinegar
•Water and dishwasher liquid
•Windex
•Baby powder? I heard about this but didn't try it. I included all the sources for reference below.

WARNING: DO NOT CLEAN THE CASE WITH THE DEVICE INSIDE. MAKE SURE THE CASE IS COMPLETELY DRY BEFORE PUTTING YOUR DEVICE BACK IN.