Honeypot in custom webforms (manual)
According to the module documentation, you can do this:


  If you want to add honeypot to your own forms, or to any form through
  your own module's hook_form_alter's, you can simply place the
  following function call inside your form builder function (or inside a
  hook_form_alter):


&lt;?php
  honeypot_add_form_protection($form, $form_state, array('honeypot', 'time_restriction'));
?&gt;



  Note that you can enable or disable either the honeypot field, or the
  time restriction on the form by including or not including the option
  in the array.
  
  You can also use Honeypot's API to modify the time delay for forms,
  add or remove protections for certain forms, etc.