The only time that players are allowed to talk during this scene is when they are physically touching each other.
This scene is meant to build non-verbal communication skills in the players. There certainly can be a fun scene in it as well. It is no fun to cheat and hold hands for the whole scene for no particular reason. There must be solid reasons for making physical contact within the context of the scene. Only speak during those brief moments of physical contact.
Averting someone’s touch.
Touch to shut up. The players have to talk constantly until they make physical contact somehow (an exercise to show how irritating constant blabbering can be).