Basically, it all depends on why you are getting your pennies cleaned in the first place. It is definitely cheaper to clean it yourself, but there are occasions where it would be more prudent of you to allow professionals to handle it. If you are planning to sell your cleaned pennies, using chemicals or scrubbing methods for cleaning could leave marks on the coins and an appraiser could easily discover this, which will greatly reduce the market value of your pennies.  But if you simply want to clean the coins for non-commercial reasons (for example, you just want a bunch of cleaned pennies you’ve found to become part of your coin collection), the vinegar/lemon juice method will be good enough. You like wouldn’t need the professional cleaning.