There's more to it than what Suity has already correctly stated.
For instance, you'd need to spend your time at away games getting off your butt and walking through the crowd, encouraging people to come sit with you. You'd need to have people at gates picking out supporters that look likely to go sit with the group and inviting them/informing them as they enter the ground. You would need to constantly hand out flyers etc telling people that the group exists, flyers which list the places to be not just next week but over the coming month or two (because not every person gets to go to every game). You would need a system that was planned ahead so that if you only ran into a person once and they weren't going to be able to get to an away game for another five weeks, they'd already know where to go.
You would need to be willing to basically achieve nothing for a year but still stick it out.
The Club would need to, as Suity said, exclude an entire bay in a prime location from general Season Tickets. This bay would essentially be empty - and look empty - for a significant period of time.
This would mean pissing off current STHs who would have their seats taken from them. It would mean pissing off the normally placid fans in nearby bays via what would need to be constant noise and movement.
Organising something via LU will achieve, essentially, nothing. Organising something via newsletter would achieve, essentially, nothing. You would need constant on the ground work from people at games to encourage people to take part.
You would need to work something out with Ticketek so that people didn't accidentally buy tickets in the middle of what would hopefully be a mob that was growing in size and noise. You'd need the bay designated so that as soon as people tried to buy tickets there they would have to agree to sit amidst the Blue & Gold Army.
The Club would need to be willing to pay for a bus that would essentially be very empty for quite some time. They'd need to be willing to pay for the banners as well as maybe some shirts. They'd need to set up a specific membership - not the general B&G Army that we have now but one that allowed people to buy into the specific group that exists simply to make noise, to sing, to have banners, to travel - to be different than the average Parra fan.
"Hey, let's post on LU!" doesn't even come close to cutting it.