He is saying he basically makes a second copy of the master channel, and that second copy is where he's doing things that effect the entire track, like the real master fader would, except that it processes the sounds a little differently. I should actually try doing that. I put all my "mastering" stuff (console, eq, comp, limit) right on the master fader. Sending everything to one extra channel before that might be a better option. I'll have to check that out.
On my master channel, I throw on a console emulation, eq (only very small changes here - if an instrument needs eq, don't make it here, go back to that instrument's channel and change it, since everything done here affects the entire mix), compression (usually around 1.4:1, faster attack and med release, only doing about 1-2db of reduction), another eq, another compressor (this one at a much slower attack and release, but I play with the settings so that the track doesn't lose high end with the release setting), and then a limiter.
With my master channels' inserts turned OFF, the music would be insanely quiet. I get most of the gain through adding around 3db from each of the master inserts' output gain. So, the console plug adds 3db feeding into the eq, then the eq feeds 3db into the comp, then the comp adds 3 db into the next eq, etc... the reason I do this is that because a lot of the master plugins I'm using feature very nice output gain - it's part of their "quality" or allure. So, instead of letting one do all the work, I take some of each of their gain. It might not be 3db, actually, it might only be about 1.5-2 for each. But you get the point. The mix is very quiet without the master plugins. BUT - I don't get all the gain just from the limiter either. That one usually is set to give about 7-8db of input, with, like I said, most of the gain of the mix coming from the previous plugins.
That's just how I do it now, though. That might changes in 6 months, for all I know.