I think Belfrybat is talking about Sharon Schamber's way of making HST's:
http://www.youtube.com/playlist?list=PL41EF4B468C4B4910
I have spent HOURS trying to make her method work, and could never "cut" them evenly. Everything up to the cutting part made sense to me, which is why I tried it. I don't know where I went wrong, but went back to drawing a line down the center of 2 squares right sides together and sewing on each side of the line, then cutting. I get the best HST's this way.
I am so curious to find out if this is the method you were referring to.