Ancient coin cleaning is a slow process. The slower you go about it, the better your results will be. I recommend storing them in olive oil and brushing once a week or so until they are clean; this can take many months. Boiling coins in the way you have removes the patina which is frowned upon; this usually destroys the details and surfaces of the coin and 'serious' collectors won't look at stripped coins. You can speed up the process by carefully removing dirt using a toothpick (or a needle, once you are comfortable with doing so without damaging the patina).
The gold coloured coin isn't gold, its actually Orichalcum, which is the roman word for brass. That coin was likely once a dupondius.
The gold coloured coin isn't gold, its actually Orichalcum, which is the roman word for brass. That coin was likely once a dupondius.























