Dark grey residue from newly purchased stainless steel kitchen items?
It could be stainless steel and abrasive residue created from polishing. 


  Method for Removal:
  
  Hand wiping with alkaline cleaners, followed by hot water rinsing.
  May require multiple applications until wipe testing results are satisfactory.


http://www.ispeboston.org/files/july_2010_tech_talk.pdf