Some options are:
regards, Fabian
You don't need to set up and use ProcessQueue for this necessarily, you can simply use the 'executeMicroflowInBackground' or ‘executeMicroflowInBatches’ java action from the CommunityCommons module. I think the ProcessQueue module is a bit heavy for this if you are not using it already otherwise.
If you use executeMicroflowInBackground, just create your own batching and deletion logic, emulate a loop with a counter variable and allow it to trigger the executeMicroflowInBackground java action as many times as needed. They run asynchronously so they will queue in the background.
Furthermore, consider retrieving and deleting your data manually from the bottom up as opposed to deleting the top objects and letting delete behaviour handle it. You can retrieve and delete lists manually much, much faster than one by one via delete behaviour.