Looks like that works. At least in my case - I just did

    def del_rw(action, name, exc):
        os.chmod(name, stat.S_IWRITE)
        os.remove(name)
    shutil.rmtree(path, onerror=del_rw)

Something more robust might check if name is a directory and os.rmdir that - I didn't need it for my case though.

Thanks.