Ah yes, this thing. When I found out about it from the guide listed on this site, I had to ask since it seemed completely, horribly abusable.
Apparently, sonicam and eredani, two top-rankers, frown upon the glitch. I was told that they don't use it, and I've noticed that their Dark boss times are lower-ranked than all their other times/scores.
As I understand it, the glitch is basically /supposed/ to be against the rules, I think. In any case, I don't use it either.