ircII behavior can be changed from the unix command prompt using signals:
use 'ps -xc' or 'ps -f' to list your active processes, then locate
the number in the PID column of the line about irc. You can then use:
  unix> kill -USR1 <pid>    to close all DCC connections
                                and terminate all EXEC'ed processes
  unix> kill -KILL <pid>    to close the irc process

You can get more information about the above commands in the unix manual:
  man 1 kill
  man 1 ps
  
See also:
  EXEC
  DCC CLOSE
