I agree. If the ports in the master cylinder are plugged then it needs to come apart and be completely cleaned.I think some folks are selling themselves short in doing it the way that was mentioned.
I did this in a pinch on my old 98 Mach z last winter in the trailer because I didn't feel like bringing it home. It shortly started hanging up again. I caught it before it melted through the entire fuel line.
I am going through that sled now as sort of a small resto and I completely disassembled the master and all in the plunger between the seals was full of rust and crud and I suspect the issue would of occurred again.