One of the largest problems encountered with the cleaning process was that the entire case of the drive was lined with 1/4” thick noise canceling foam that had degraded over time. Any contact with the foam would cause it to crumble into dust, something potentially disastrous if it were to contaminate the disk cavity, and ultimately all of it needed to be carefully removed. Additional problems were encountered from the large number of spiders that had taken up residence inside the disk drive, as well as a 3”-diameter (thankfully abandoned) “mud dauber” wasp nest that had been constructed within the drive.
It's worth a read, and the whole story is surprisingly gripping. The other great thing about the article, though, is the number of old illustrations that document an approach to computing that is now absent. Where it was assumed that every component needed to be documented in the case that a new piece would have to be recreated rather than simply discarded and repurchased.