Noisy Miners using Brown shield-bug scent

I recently observed a group of Noisy Miners catching Brown shield-bug/stink-bugs on the base of a Eucalyptus tree at Murwillumbah NSW. What followed was interesting as the birds gave the bugs a good hiding with their beaks on the ground then proceeded to vigorously rub the bugs under their wings before discarding them. This behaviour with 7 Miners went on for ~ 20 minutes. I checked the activity area when the birds left and found many wounded bugs and observed a pungent stink-bug odour. Maybe, as suspected with “anting”, the birds were de-lousing? Any similar observations from birders? Clive Easton