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
