I have two plate chillers back to back and was considering forcing out the last of the wort with oxygen. The same oxygen I use with an inline stone mounted in a tri-clamp, but then connected to the hose that came from the kettle to force all possible wort out of the system. At least it would be sanitary as opposed to using compressed air. I'll try it this weekend.
I'm also brewing extra to compensate, and it's about 1/4 gallon lost in my case.