here is the specific quote: www.bitsavers.org/pdf/dec/disc/RM05_Handbook.pdf pages 2-43 and 2-44 " CDC does not recommend head or media cleaning on the 9766. <- same heads as RM03/9762 The tolerances involved are much more critital than the RP06 or similar drives. Due to the 'Burnished media' technology used on these packs, the normal pack cleaning procedures tend to leave a residue on the platter surfaces. The media requires a special power wash cycle to insure that all the residue is removed. Again, only a keen eye trained to recognize a media defect can spot a problem inspecting a pack. CDC recommends a program of media inspection at certain intervals but will not recommend any cleaning. Therefore a clean environment and proper storage of media to prevent pack contamination is strongly suggested. "