I make each student have a helper and they have to clean up the station
before the next pair can print - I only let 4 pairs print at once. My
students do 4 blocks so they always have something to work on when they
are not printing so that helps. For the end process when they are "done"
they make an accordion book to display their prints so that keeps everyone
busy right to end - some students haver no book or do that part at home
because they are the lagging ones. I am a print witch about cleanliness
and ink being cleaned up promptly etc.