Are you trying to delete an executing/initiated/suspended work flow or are you trying to kill the WF maps you created.
The approach should be different for both.All your maps is an object in dtree and dversdata with subtype filter=154 which is for workflow.However if your intention is to go after executing/archived workflows the API says to use
DeleteWorkflow .This is from the API reference
If the workflow specified by the workID parameter has not been stopped using the StopWorkflow function or completed by performing EndTask on the last task, the DeleteWorkflow function returns Error.
Successful execution deletes the workflow from the database, including the work package (attributes, attachments, comments, and forms), and deletes the audit trail as well.
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If you have a mailid I will send you a sample java file that will query for a specified workflow.You can see if you can use them by passing a dynamic list of all workflowids