Wow, opening the drive and wiping off with your shirt and then you want to return it... I would save the postage for a new drive.

Remembering one time when I was in school, we went to se this laboratory where
they recover data from crashed harddrives. They shoved us the 'cleanrooms', the techs. working in there was not allowed to work there for more that 4 hours per. day as the environment was too clean for human body.
After that they shoed us a video where they had taken the cover off of a harddrive, they then put some sugar onto the platters, the sugar just bounced of as the head moved. Then they blew some smoke onto the platters, the platters was destroyed after a little while as the smoke particles was so small that they got between the heads and the platters.

TommyE