title_body: How can I clean a rusted moka pot?
upvoted_answer: Based on your photo your pot appears to be made from aluminum based on the white corrosion.  This will make cleaning it a bit harder overall but no worries!  A great product that will take care of this issue for aluminum or stainless (many other materails as well) is Bar Keepers Friend. 
  
  From Wikipedia's article on Bar Keeper's Friend:
  
  
    Unlike more abrasive cleaning powders such as Comet and Ajax, Bar Keepers Friend uses oxalic acid as its primary active ingredient. A similar abrasive cleaning product, Zud Heavy Duty Cleanser, also contains oxalic acid. Prolonged use and extended skin contact may cause irritation, peeling and contact dermatitis, which is avoided by wearing gloves. The product can also be an eye irritant.
  
  
  I just used BKF to clean my stainless percolator pot and it did a great job it looks new!  I had baked on brown residue and it took it off in less then a minute.  Now my pot looks almost new.  
  
  For your specific pot I would get a good scrub brush and some BKF and give it a few minutes scrub and it will look new again!  I think BKF may be one of the most underrated tools for us coffee junkies.  It gets everything so clean, it even has taken those impossible stains out of the bottom of some of my well used coffee cups.  
  
  To prevent corrosion issues in the future the best course of action is to clean it and dry it completely after each use and not let coffee or water sit in it for prolonged time.