Compressed air didn't do a thing for me. Once I took it apart and basically doused the wheel in contact cleaner it started working like a brand new unit again!
I was stupid enough to bring my lunch in the same bag as my Jb3 to work one day (authentic homemade chinese[real stinky]) the tupperware leaked alll over the jb3. I didnt know at all what happened untill 2 days later (WTF IS THAT SMELL!!!!!). I almost cried when I pulled it out, it was dripping, everything inside was coated in soy/ginger/garlic who knows what sauce.
CONTACT CLEANER TO THE RESCUE!!!!!
it still has a bit of an old food smell but it works like a charm.