entity reference

I am trying to create a rule which fires after modifying node content. Specifically i want to modify the entity reference field values of all the node entities provided by vbo. So i created the rule and the component as shown below.
My problem is that i can not find a way to empty the entityref list of all node entities before the loop, maybe my whole approach is wrong.

Hey all,

Just wanted to share some rules I built as I've been racking my brain all afternoon on how to do this but eventually figured it out using Drupal 7 Rules 2 with a Rules Component. Might be useful to some of you, might not be but here it is anyway!

I have an Event node which contains an Entity Reference to a user. The user has a "credits" field. I needed to remove a credit from the user's account every time they attended an event. So I created a rule that uses a "Before saving content" event and a "Content is of type" condition.