Column up and down the hall, ones facing each other (man above), the other men standing behind the first man in order, women similarly.
A1: Ones side R. Set; turn single while passing L shoulder to face the next.
A2-3: Same with the next and the next.
A4: Same with the next, but after passing face back to same person.
A5-8: The same but side L, all finishing home.
A9-16: As A1-8 but arming instead of siding.
A17-19: Ones start cumulative hey with hands, all finishing home.
Playford and Sharp say it's longways for as many as will, but it's always done with four couples. There's also a "fair shares" version where the fours don't go to sleep!