First of all, thanks for all of the advice.
Update for prosperity:
I enlarged the holes that I could reach to 13/16", and commenced war. It was a major battle indeed, especially in the wing walk area where the skin was already installed and I could not enlarge the holes. The first 6-8" of conduit was destroyed in the pulling process. I cannot even imagine how you guys managed to pull this stuff through the entire wing using only 3/4" holes.
One more wing to go and then I will secure everything with 3M 5200 urethane.
Over and out,
David
Bend the conduit tube so that a conduit 'ring' pops through on one side and then bend it the other way to pull the rest of that ring through. Pull on the tube all the while. Do 5 or six rings at a time on each wing rib in succession so that the conduit proceeds down the wing span like a caterpillar crawling along. Couldn't be done after the skins go on.
This worked for me but it is still a pain.
By the way, take a one inch piece of this stuff, light it and watch what happens. Then decide whether you want to use any of it in the cabin, especially up at the firewall.