If lobbyists aren't visitors, then reporting their visits becomes painless. Just hire the lobbyists, as the Obama admin has done.
Obama, pre-election: "I am running to tell the lobbyists in Washington that their days of setting the agenda are over. They have not funded my campaign. They won't work in my White House."
Obama, pre-election: "I am running to tell the lobbyists in Washington that their days of setting the agenda are over. They have not funded my campaign. They won't work in my White House."
Obama admin, post-election: http://www.prwatch.org/node/8167