The collector should take great care in the cleaning of the coins. The coins should never be cleaned if one is not sure about the process/result of cleaning especially with any chemical or wire brush. However it depends on how you would like to deal with your coins. Since I like to see my coins all shiny and clean, I used a chemical which is easily available in the Indian market for cleaning copper vessels and utensils. The chemical is available in the name of 'PITAMBARI'' and can be easily found in any nearby grocery store. I have cleaned all my republic india coins except silver coins with pitambari and a soft toothbrush and I am satisfied with the results.
Some of the other methods of cleaning coins are described as under :
(a) Silver Coins may be cleaned with soap or tooth-paste and rubbed between the thumb and the index finger. Personally I have cleaned all my silver coins with Colgate tooth powder and the results were excellent. I have applied little bit of Colgate tooth powder and rubbed the coin with a soft bristle toothbrush for cleaning my silver coins. However I would recommend doing this on your own risk.
(b) Copper, brass and bronze coins should be dipped in sour curd (Khatta dahi) and rubbed with soft tooth-brush. The coins can also be cleaned in Tamarind (Imli) and later with Lemon juice diluted with water.
(c) Copper and Bronze coins may have greenish deposit (Patina) on them. These can be cleaned by dipping them in coconut or seasame oil and rubbing with hard tooth-brush. Tamarind water or Lemon juice can also be used. Any edible oil may also be applied to all obsolete copper; Bronze and Brass Coins, for protecting them from the greenish deposit.
However nothing should be applied to UNC coins.
