When the conversation between the two conversationalists begins to flag, the CBAR is invoked by one of the two mates raising the tube up to his/her mouth and speaking through it. The other mate follows suit by upraising his/her own tube and continuing the now-flagging conversation. As the discourse winds down, the two participants in the CBAR begin to stuff cotton balls in their own cardboard tubes, whilst continuing the verbal exchange. Eventually enough attenuation will have occurred so that talking is nigh impossible through the tube. At this point, the most attenuated converser looks down at his tube with mock incredulity and shrugs. This action is reciprocated by the less attenuated converser. Conversation is now ended and the two mates part ways.

An elaboration for the decadent: after the shrugging, the conversationalists can sign 'Roger Wilco' to one another. This addition, however, is only for owners of Rolls-Royce Merlins.

(Thanks to [Rods_Tiger]'s annotation on 'The Last Word', Aug 25, 2001.)