De-Dupe associated contacts in a workflow or batch email

[AMorey]

With flexible associations and custom objects, we have many contacts associated to many child and parent companies.  

When we create campaigns based on criteria at the child company level, it is emailing all associated contacts multiple times.  If a contacts is associated to 7 child companies that meet the trigger criteria they are getting emailed 7 times.  

I need a feature to ensure the workflow will de-dupe my contacts associated to the child companies or parent companies in a workflow.