I've never heard of that method either, but it makes lots of sense. I've had good luck just disconnecting the old master cylinder,then bench bleeding the new one & installing it. You can then bleed the air out of the brake lines at the master. Just crack them a bit while having an assistant pressing down on the brake pedal till only fluid comes out.[don't forget to wipe off or flush off the excess fluid or it will destroy the engine room paint!] 99% of the time you won't have to bleed the calipers out at all, since the master's at the highest point of the system & not much fluid is lost. George's system would also work better if the master is bench bled. Bench bleeding can be less messy if you have some plastic ends to screw in the brake line holes with attached rubber lines that recycle the fluid into the top of the reservoir. Most parts houses have these. They sometimes come with the new or rebuilt masters. Just get the ones that fit your master cyl. Hope this helps.

Mike M.