when a workitem is deleted, does its attachments get deleted too (if it was the last attachment referencer)?

we have been testing our project copy utilities, one run on our production machine for timing estimates..
we will delete all the workitems and do a new run on the final cutover..

but I realize now that we created a lot of attachments that need to be redone too..
how to clean them up is the issue.. any ideas? query all workitems with attachments, then process the list and delete them one by one?

thanks for any guidance..