Cleaning mouth by water. In this one takes a sip of water, and drinks it It is repeated three times and it is done normally before doing any worship, after finishing food, and before doing any religious activity. Aachaman precedes all rituals or ceremonial sipping of water and touching the various parts of the body like eyes, ears, nose, chest head etc with wet hand in the prescribed order. This process invokes the life-energy to protect the performer. This clarification is given by sage Bharadwaaj that Praanaayaam is done for internal cleanliness. Aachaman is the not only the process of purification but is the process for success of the ritual, as Praanaayaam is for cleanliness. In the ritual connected with the corpse (Pret), Aachaman should be done in the beginning and end. This is true for every ritual for the success of the ritual.

Types of Aachaman
Shree Naaraayan said :-- "O Naarad, There are six kinds of Aachaman :-- (1) Shuddh, (2) Smaart, (3) Pauraanik, (4) Vaidik, (5) Taantrik and (6) Shraut. The act of cleaning after evacuating oneself of urine and feces is known as Shuddh Shauch. After cleaning, the Aachaman, that is performed according to rules, is named as Smaart and Pauraanik Aachaman. In places where the Brahmaa Yagya is performed, the Vaidik and Shraut Aachaman are done. And where acts, eg the knowledge of warfare, are being executed, the Taantrik Aachaman is done. Then he should remember the Gaayatree Mantra with Pranav (Om) and fasten the lock of hair on the crown of his head, thus controlling all the hindrances (Vighn Bandhan). Sipping again, he is to touch his heart, two arms, and his two shoulders. After sneezing, spitting, touching the lower lip with teeth, accidentally telling a lie, and talking with a very sinful man, he is to touch his right ear (where the several Devtaa reside). On the right ear of the Braahman reside Fire, Water, the Ved, the Moon, the Sun, and the Vaayu (wind).

Many people say that Aachaman are of three kinds - Shruti (Shraut), Smriti (Smaart) and Puraan (Pauraanik).
(1) Directions for Shraut Aachaman are given in Tattireeya Aaranyak, where it is said that this Mantra "Vidyudasi Vidyame Paapmaanam Ritaat Satya Mupaimi" - meaning "You are lightening, remove my sins. Through Truth I attain Truth." should be recited. Hands should be washed, water should sipped three times, the palm should be washed again. Head, both eyes, both ears and both noses should be touched.

(2) Smaart Aachaman is divided into two kinds - Shraut and Smaart. In Shraut Aachaman, the first three names of Keshav - Naaraayan and Maadhav are remembered and water is taken as Brahm Teerth. Water is sipped three times with the recitation of three Pad of Gaayatree Mantra in succession. The next, 21 body parts are touched along with the recitation of 21 Mantra - 9 Abling (Aapohishtaa etc), 7 Vyaahriti (names of 7 Lok preceded by Om), and 3 Pad of Gaayatree (Om Aapo Jyoti Raso mritam Brahm Bhoor Bhuvah Swarom). With this it is expected that the 5 Gyaanendriyaan, 5 Karmendriyaan, 5 Mukhya Praan, 5 subsidiary Praan and the mind all are purified and the mind also becomes calm.

There is a system where instead of Keshavaaya Swaahaa, Rig Vedaaya Swaahaa, Yajur Vedaaya Swaahaa, Saam Vedaaya Swaahaa are repeated.

Smaart Aachaman process is laid down by Manu, Yaagyavalkya and other Smriti writers. In this process water is sipped thrice, lips are washed and mouth and several sensory organs are touched. Smaart usually recite a prayer to Ganapati (Shuklaamabar Dharam Vishnum Shashi Varnam Chaturbhujam Prasann Vadanam Dhyaayet Sarv Vighnop Shaantaye)

(3) Puraan Aachaman is given by different writers - water is sipped three times, several parts of the body are touched, each single operation is accompanied by a different name of Vishnu or Shiv. The method normally adopted in this process is with the names Keshav, Naaraayan and Maadhav.

Then one is to go to a river or any other reservoir of water, and there to perform one's morning ablutions and to cleanse his body thoroughly. For the body is always unclean and dirty and various diets are being excreted out of the nine holes (doors) in the body. The morning bath removes all these impurities. Therefore the morning bath is essentially necessary. The sins that arise from going to those who are not fit for such purposes, from accepting gifts from impure persons or from the practice of any other secret vices all are removed by the morning ablutions. Without this bath, no acts bear any fruit. Therefore everyday, this morning bath is very necessary. Taking the Kushaa grass in hand, one is to perform one's bath and Sandhyaa.

If for seven days, the morning ablutions are not taken; and if for three days, the Sandhyaa are not performed; if for twelve days, the daily Hom be not performed, the Braahman become Shoodra. The time for making the Hom in the morning is very little; therefore lest ablutions be done fully which would take a long time and hence the time for the Hom might elapse, the morning bath should be performed quickly. After the bath the Praanaayaam is to be done. Then the full effects of bath are attained. There is nothing holier in this world or in the next than reciting the Gaayatree Mantra. It saves the singer who sings the Gaayatree; hence it is called Gaayatree. During the time of Praanaayaam, one must control one's Praan and Apaan Vaayu to make them equal. The Braahman, knowing the Ved and devoted to his Dharm, must practice Praanaayaam three times with the repetition of Gaayatree and Pranav and the three Vyaahriti (Om Bhu, Om Bhuvar, Om Swah).

Aachaman precedes all rituals or ceremonial sipping of water and touching the various parts of the body like eyes, ears, nose, chest, head etc, with wet hand in the prescribed order (Nyaas). This process invokes the life-energy to protect the performer.

There are three types of Aachaman - Poorn Aachaman, Shraut Aachaman, and Smaart Aachaman.
The first three names of Keshav, Naaraayan and Maadhav are remembered and water is taken as Brahm Teerth.
The next 21 names are taken to touch different parts of the body and it invokes the deity who protects that part.
With this it is expected that the 5 Gyaanendriya, 5 Karmrendriya, 5 Mukhya Praan, 5 Subsidiary Praan and the Mind are purified.
It is expected that with this process, the mind also becomes calm.

There is a system where instead of Keshavaaya Swaahaa, Rig Vedaaya Swaahaa, Yajur Vedaaya Swaahaa, Saam Vedaaya Swaahaa are repeated.
The method normally adopted is the Poorn Aachaman with the names Keshav, Naaraayan and Maadhav.

It is believed that while touching the different parts of the body with wet fingers and invoking the names of the Adhi Devtaa of that part, the body and mind becomes pure so that further rituals are successful.
It is also believed that at the tips of thumb, the forefinger, and the small finger there live Brahm Teerth, Devtaa Teerth and Prajaapati Teerth.