put-panels-down.sh

#!/bin/bash

function getPanelIdImpl() {
  PANEL="`wmctrl -l | sed -n -e '/xfce4-panel$/ s_ .*$__ p' | sed -n -e $1' p'`"
}

function getPanelId() {
  getPanelIdImpl $1
  while [[ x == x$PANEL ]] ;do
    sleep 0.5s
    getPanelIdImpl $1
  done
}

function putPanelDown() {
  PANEL=""
  getPanelId $1
  wmctrl -i -r $PANEL -b add,below
}

putPanelDown 2
putPanelDown 3
putPanelDown 4