<?php

$configuration  = new Ssh\Configuration();
$authentication = new Ssh\Authentication\None();

$session   = new Ssh\Session($configuration, $authentication);
$directory = '/some/directory';
$adapter   = new Gaufrette\Adapter\Sftp($session->getSftp(), '/some/directory');

ssh2_exec($session->getresource(), sprintf('rm -r %s/*', $directory));

return $adapter;