How to set a multi line value from drush vset

I was trying to add a value to the drupal antibot antibot_form_ids variable.

drush vget antibot_form_ids 

returns a string separated by /r/n Adding just a value to this string isn’t just enough. If you do a
drush vset antibot_form_ids 'webform_*\r\nuser_login\r\n
and so on you end up with exactly this value in the form field of the config area.

So how can it be done?