Yeah, the whole thing with getting the coil away before turning it off is to be sure that you don't remagnetize it.

If you have the coil anywhere near the TV when you plug it in or unplug it (plug it out?) (English!), and you happen to make the electrical connection at a portion of the electrical cycle where there is lots of voltage, there will be a burst of magnetism. This is obviously worse on shutting off the coil, because you expect to be demagnetized at that point. The degausser takes advantage of the constant repetitive reversals of voltage polarity and thus magnetic polarity; when you slowly move this reversing field away from the tube, it magnetizes in one direction, then demagnetizes and remagnetizes a bit less in the other direction, etc so the magnetization becomes less and less as you move away. Then you unplug it and BAM! you can get a magnetic pulse a lot larger than the ones you get when it is plugged in.

Thus turning it 90 degrees helps, too, as noted, because that directs the magnetic field away from the tube.