Can't you dial somebody's number who's in the conference and they'll patch you in? I've never used Skype but if that's not a standard feature it should be.
They have to have the Skype-In service, which costs money. Also, only the person who started the conference can add other people in. And if the conference starter, for whatever reason, has to drop, the whole conference dies.
There wasn't really anything wrong with the original plan; talk in 752, and when X or Jay-D come in and flood, just go to the next room, or organize a secret room only the non-flooders know about.
But then again, they switched over to the new number that only has 1 room, so that plan's pretty fucked now.