Chlorine bleach has the potential to be one of the worst things to put in a gas tank because it can react with the chemicals in gasoline and form an acid. What theoretically can happen is this acid can cause premature rusting of the gas tank and fuel lines and cause a stalling problem. Still, it may not cause any long-term engine problems. Simply flush out the gas tank and fuel lines and then replace the fuel filter.
Even if a substance doesn't get all the way to the engine, it can harm the fuel line or the gas tank itself. Be sure to keep the gas cap tightly closed, and locked, if possible to keep out all foreign substances.
In recent news, if you are looking for employment, you might want to look into becoming an auto mechanic. There is a shortage of mechanics and the Labor Department predicts it is only going to get worse in the years to come. The demand for auto mechanics is expected to grow about 17% from 2010 to 2020, adding 124,800 jobs for a total of 848,200.