Correction : I mixed up markmeiller's response with the winscp one. markmeiller's ftprequest is a no-go because it doesn't support sftp which is core to the article.

I will stick to the psftp solution, it is fairly well documented and I am not concerned so much about leaving the files behind :

1) I can clean up the files even upon failure of the process, just by separating cleanup in separate process that is next step in the job (both on job failure and success)

2) directory is on a server with very limited access

etc