$this->_getRequestRewriteController()->rewrite();

protected function _getRequestRewriteController()
{
    $className = (string)Mage::getConfig()->getNode('global/request_rewrite/model');

    return Mage::getSingleton('core/factory')->getModel($className, array(
        'routers' => $this->getRouters(),
    ));
}

rm -rf var/cache/*