Describing the methods of purifying different articles, Lord Vishnu reflected on the instructions which sage Yagyavalkya had once given to other sages in this regard-‘Substances like gold, silver, conch, vegetables, rope, leather articles, etc. become pure once they are washed with water. In the same way, utensils made of wood or animal’s horn become pure after they have been chiseled. Utensils used in yagya become pure after they have been rubbed with mud and then washed with water. Washing woolen and silken clothes with tepid water or cow-urine make them pure.
Land is purified if it is coated with cow-dung. Copper vessels, articles made of lead and Tin vessels become pure if cleaned with a solution of alkali, acid and then washed with water. Iron and bronze vessels become pure if cleaned with ash and water. The followings are believed to be pure- sun-light, fire, cow, horse, earth, air, dew-drops, food-grains up for sale in the market, etc. A man should perform Achaman in the following circumstances- after his bath, after drinking water, after sneezing, after waking up from sleep, after having food, after having a walk on dusty path, after changing clothes, etc.