The following is the ritual I use to create holy water, which I use in all sorts of projects and rituals from a daily cleansing of the self to creating complex solutions for later work. The water has the effect of driving off evil and suprressing pain while increasing virtue and well-being. Besides, they say that cleanliness is next to godliness. Water is a critical component of religion, magic, and spirituality across many cultures and time periods, and has been made or blessed in as many ways: some of the ancient Greeks dipped a torch of sacred fire into a vessel of water, while the rivers Jordan, Tigris, or Ganges have all been claimed to be holy entirely. I compiled the ritual below from three sources: the Key of Solomon (book II, chapter 11), a Catholic ritual for using holy water, and a Greek Orthodox ritual for creating holy water (the Mikros Agiasmos, by way of Fr. Rufus Opus’ Red Work series.)
Holy water should be made in the day and hour of Mercury (especially if the water is to be used for magical purposes) or Jupiter (for religious and blessing purposes), when the Moon is waxing; I prefer the day and hour of Mercury generally. Holy water is made from, perhaps shockingly, fresh water; clean water from a spring, stream, or well is ideal, but even water from the tap will do so long as it’s clean, clear, and tastes good. Salt is also needed, preferably uniodized white sea salt or rock salt, one teaspoon for every cup of water. Hyssop, basil, or other herbs may be used in addition to or instead of salt and can result in a more potent version of holy water, but may not keep as long bottled or stored. I prefer hyssop for purificatory or spiritual baths.
Before making the holy water, being in a purified state is suggested. Banish, bathe, cleanse, fast, and pray to enter into a spiritually clean state before making holy water in this manner. Making holy water in other ways may not require this, but it’s hard to interact with the Divine to make something so completely clean with dirty hands.
Place the salt in a small container. Bring the water in a pot to a rolling boil, and continue boiling for three minutes. Turn off the heat. Say the following over the salt to exorcise and bless it:
Tzabaoth, Messiah, Emmanuel, Elohim Gibor, Jehovah, O God, the Truth and the Life, deign to bless + and sanctify + this creature of salt, to serve unto us for help, protection, and assistance in all places and at all times, and may it be a succor unto us. Almighty God, we ask you to bless + this salt as once you blessed the salt scattered over the water by the prophet Elisha.
I exorcise you so that you may become a means of salvation for believers, that it may bring health of soul and body to all who make use of you, and that you may put to flight and drive away every apparition, villainy, turn of devilish deceit, and every unclean spirit from the places where you are sprinkled, adjured by him who will come to judge the living and the dead and the world by fire.
Wherever this salt and water are sprinkled, o Lord, drive away the power of evil and protect us always by the presence of your holy Spirit.
Pour the salt in a cross formation into the water. Say the following over the mixture to bless the water with the now-cleansed salt:
Lord God Almighty, creator of all life, of body, and of soul, we ask you to bless + purify + and sanctify + this water by your heavenly blessing. Grant it the grace and blessing of the Jordan and the power to cleanse all defilements, to heal all illnesses, and to drive out evil spirits and their deceits and snares. By the power, action, and grace of the all-holy Spirit, let this water be for the cleansing of the soul, the calming of passions, the expulsion of all evil, the increase of virtue, the healing of illnesses, the sanctification of homes and of all places, the driving out of all destructive and evil-doing spirits, and the reception of your grace for those who drink this water in faith, receive it, or are sprinkled with it. Lord, in your mercy give us living water, always springing up as a fountain of salvation; free us and our body, our soul, our spirit, our and mind from every danger, and admit us to your presence in purity of heart. As we use this water blessed by your grace in faith, forgive our sins and save us from all illness and the power of evil.
Say Psalms 102, 54, 6, and 51 over the water. Say the following:
Lord, holy Father, look with kindness on your children, redeemed by your Word and born to a new life by water and the holy Spirit. Grant that those who are sprinkled with this water may be renewed in body and spirit and may make a pure offering of their service to you. Shine on it with the light of your kindness. Sanctify it by the dew of your love, so that, through the invocation of your holy name, wherever this water and salt is sprinkled, it may turn aside every attack of the unclean spirit, and dispel the terrors of the poisonous serpent. And wherever we may be, make the holy Spirit present to us, who now implore your mercy. Amen.
Stir the salt into the water until completely dissolved. Say a thanksgiving prayer (e.g. the Prayer of Thanksgiving, or the Lord’s Prayer with a Glory Be). Bottle or store the water as desired. Light a candle and some incense (preferably frankincense) by the containers of water as an offering to God, and let the candle and incense burn out before using the holy water. So long as it’s kept free from contaminants, it should keep for a while without bacterial or fungal growth.
With such consecrated water, I then use a blessing of chalk to consecrate and prepare the stuff for use in rituals and workings. Take chalk in a day and hour of Mercury, preferably when the Moon is waxing and in the sign of Virgo. Sprinkle the chalk with holy water and say the following over it.
O God, heavenly father, eternal spirit, fountain of light, present in all places and father of all things, who fashioned the world in the seven days of creation, bless this creature of chalk that it may be used for the aid, defense, and salvation of the human race. O Lord, through the invocation of Your holy name ELOHIM TZABAOTH, grant this chalk the power and blessing to preserve that which is just and true from losing its justice and truth. Just as you provided safety for your Word eternal, so too may this chalk provide the same for us and in all purposes that it shall serve us. Amen.
This consecration could also equally be used for any writing instrument, like pens, pencils, or charcoals. For the less Abrahamic or Hermetic, an appeal to Mercury, Hermes, Thoth, Odin, or a similar scribe or language god would work as well.