Powders start losing their potency after 6 months and maybe used up to one year after which they may not cause harm, but they will not be effective. Herbs that are bitter, slightly pungent and astringent in taste like cloves, gum arabic and black long pepper are best used for oral hygiene in dry and powdered form. Daily massage of the gums with a finger dipped in sesame or mustard oil is also a healthy practice. Herbs are associated with six tastes - sweet, sour, salty, pungent, bitter and astringent. Tamarind, lemon and gooseberry are slightly heat producing and sour to taste.
Rock salt is recommended, as it is cooling and beneficial for the eyes.
Turmeric is an astringent and cooling herb. Various herbal formulae combine all the 6 tastes in order to ensure a balanced combination for daily intake. Some of the easily available herbs and their benefits Ginger - Ginger increases immunity and stimulates the digestive, respiratory and nervous systems. It helps revitalise sluggish circulation and to remove dullness and inertia and can be used both externally and internally. It can be applied on the forehead as a paste for cold-related headaches and on the chest for relief from colds and coughs.