Unfortunately I am not not sure if this will work? Could perhaps someone clarify?
Refer following steps to set Retention / Information management policy :
- Goto list settings
- click on Information management policy settings
- click on Item content type
- tick on Enable retention check box
- click on Add retention stage
- fill out the Action and the Event
- Click OK
Remember this retention policy will not run immediately after you are done with the set up. Because "Information management policy" and "Expiration policy" are the 2 timer jobs which are responsible for retention policy.
You can check when the job is scheduled to run. refer this link - https://social.msdn.microsoft.com/Forums/sharepoint/en-US/e6625f27-48ad-4594-8694-b9b33f4cda57/when-do-retention-policies-run-by-default?forum=sharepointdevelopmentprevious
Refer following link on how to set retention policy for more information(But you will have to make changes to your policy according to your need):
The OOTB way to do this would be to create your workflow as you want it and add a stage at the end. In this stage put in a Pause action. You can set this for 1 day (or 24 hours). For your Transition to stage, have it redirect back up to the first stage. In the first stage do a check to see if create date is less than today minus 7 days. If true use the delete action to delete current item. don't put an else on this as it will need to run thru to the next stage to pause again if its not been 7 days.