The cleaning procedure in the laboratory I used to work in for removing
organics from silicon wafers was typically acetone, then isopropanol, then
ethanol, then a deionized water rinse and nitrogen dry. We did use piranha
solution on occasion when it was particularly caked on (like really old
photoresist). When I cleaned an ST-4051 in the lab, I skipped the acetone.
That worked quite well; the drive worked just fine after that (and a
low-level format).
Kyle