Personally, I have a plasma I bought 5 years ago that I never broke in, I didn't know about it then? I pulled it out of the box, set it up and proceeded to play about 4 hours of Xbox on it, the absolute worst thing you can supposedly do to a new plasma. 5 years later it's my daughter's gaming and Roku TV and looks as good as the day I bought it.
Just to add, the panel aging process that some call breakin is for people that need a tv professionally calibrated asap. So they run slides continuously for a hundred hours or so then call a pro in for a cal. You can get similar results just watching tv but it can take longer and it tends to age the center of the screen a little more. I see no value to wasting the tv on this unless you are needing a cal pronto.
The plasmas tend to color shift the most in the early hours and people tend to see pic quality improvements in the first 100-200 hours whether watching tv or running slides. So it's up to you if you need to do this. If you do I recommend putting slides on a usb drive or sd card and letting them run from the slot in the tv. If you need the slides here they are. Unzip and add to a clean formatted drive with a windows PC.