Here is what I do to remove even the most stubborn IR (nothing else worked, WOW, Slides, etc..):
First, understand that the fastest burn-in or IR created when a flash of white appears on a completely black screen,
for example your enter the Menu on a black background, or using the Plasma as the main PC monitor.
To prevent this change the background to grey or white if you use a PC connected to the Plasma, or as your Home Screen TV background image.
Now download this small (2MB) video file: IR Remover Video
This video is a thin (important) line that moves across the screen that will simply "cook" phosphors quicker than anything else (and remove IR).
Its important that its THIN (unlike the one that's in the menu) to simulate the quick flash of white on a black screen.
Open this with your PC Media Player (I use MPC-HC for a reason) and play this file with maximum Contrast.
I also select in MPC-HC to exit after playback to return to the white background.
Now lower the Contrast back to normal.
Maybe it can be done on a USB stick with the TV built in Media Player?
I'll try later.
I also found a great method to clearly see all the IR's on a Panasonic TV.
1. Click the 3D button on the remote.
2. Click RED button (Manual).
3. Select 2D -> 3D.
4. Change your background to Black (try not to enter the menu).
5. Look for IR.
What 3D mode does is elevate the native black level of the TV along with all the IR so that they are CLEARLY visible.
You can return to normal 2D mode by clicking 3D button on the remote and selecting 2D.
Make sure you return the white background.
If something is not clear, ask.
Hope that helps.