I have been using "Circulate" as the call, after seeing that people got the general idea of the figure during teaching. I have always liked this technique borrowed from another caller (I forget who now...) for teaching purposes: During the walk-through (after seeing that people have gotten into the correct positions to begin the box circulate from the previous figure - for example "men facing out, ladies facing in" in long wavy lines) I give this "rule":
(after balancing):
When you are facing into the set, you will walk straight across (to the other line), and take hands with those looping to face you.
When you are facing out of the set, you will loop over your right shoulder taking hands with the people coming towards you, (on the same side) in a wavy line.

I have avoided calling different roles, like "Gents cross, ladies loop", and the dancers seemed to get the "face in means cross", "face out means turn to the right to face in on the same side"  When I taught this to a less experienced group of dancers, they all got it, and also noticed on their own that they had sort of a shadow, and said they liked realizing that they were heading toward a familiar face to rejoin hands.
I think the best part of a box circulate dance is when one partner is approaching another as they are turning to go into a balance and swing, as most of them do.

Valerie Cohen