According to ancient tradition, if one owns a pusaka heirloom keris, the sacred artifact generally requires frequent attention. This means that the owner should clean the keris every now and then, or whenever s/he feels necessary. Traditionally people clean their tosan aji (sacred metal) items on a particular day (or night) that is considered an auspicious occasion for performing the ritual cleansing of kerises, tombak spears, pedang swords, kujang cleavers, golok knives, and other kinds of tosan aji weapons. A so-called auspicious event can be calculated by using the Javanese calendar in conjunction with astrological alignments. Once an auspicious date is selected to perform the ritual, one first needs to prepare a set of offerings before one can begin with the cleaning process of the sacred pusaka items.
Traditional offerings for a keris consist of various kinds of foods, such as rice porridge, cake, and fruits, along with flowers and incense. However, the exact list of offerings can differ from one region to another, depending on the availability of the foods in that particular area. But, whenever possible, people aim to follow the traditional customs as prescribed by the high aristocrats of the royal court (‘keraton’) of Yogyakarta and Surakarta.
Since ancient times, the royal keraton palace of Yogyakarta and the Sultanate of Surakarta prepare the following offerings before their astonishing collection of royal pusaka items are ritually cleansed: red rice porridge, white rice porridge, red rice porridge mixed with white rice porridge, white rice porridge divided in four parts separated by peanut sauce, half a plate of white rice porridge with red rice porridge on the other half, two bunches of ripe bananas, a whole coconut, a (farm village) chicken egg, a handful of uncooked rice, and palm sugar. Besides foods, drinks are also offered, namely one glass* of black tea, and one glass of black coffee. For the rest, the long list of offerings is finished off with incense, red roses, white jasmine, and ylang flowers. Yet occasionally some sweets, cigarettes (without cloves), kretek cigarettes (with cloves), and cigars are added to the conventional list of offerings. In rare cases, opium may be included as well.
Next, mantras will be chanted, and prayers are performed. These are usually in Javanese, whereas Hindus and Buddhists often chant in Sansekerta (Javanese Sanskrit), while Muslims, of course, recite their prayers in Arabic.
Regular performance of traditional rituals for kerises is generally seen as something essential in order to maintain the balance between the human realm and the spiritual realm. Likewise, frequent maintenance of a sacred pusaka item, is believed to appease the khodam spirit that may reside in some kerises, which, of course, is crucial for maintaining a harmonious and beneficial relationship between the owner and the keris.
*Indonesians drink tea and coffee from a glass, unlike Westerners who drink tea and coffee from a cup.