Natron is a salt like item which is used for purification of the body before and after death. It generally is used to refer to refers to sodium bicarbonate, sodium chloride, sodium carbonate, and/or sodium sulfate.
In ancient times it was mostly used to prepare a body for the afterlife once the person had died. It was used because it dried out flesh, removed the grease held in the body's cells, and acted as a disinfectant. These are all important things to consider in light of the importance of the physical body or Khat after death.
Natron was used for the making of faience (a material which was used to make many of the small figurines Egypt is known for). It was used to produce the dark blue color common in Egyptian figures, as well as used in the production of soap, mouthwash, and toothpaste. It was also used in the production of glass and to preserve meats. It could be included as an antiseptic, used as a bleach, and used to produce leather. It was also used in the production of incense, a very important ingredient to Kemetic temple work in the ancient world.
Natron came from the Wadi Natrun (a dry salt lake/swamp) in ancient times. Today it is illegal to export natron from Egypt, due to a law in the country intended to protect these rare natural resources. It can still be found in Egypt however.
Natron is used in the modern day most commonly among traditional Kemetic practitioners as part of a purification ritual before going before the images of their gods. Several other purification requirements are necessary as well so as not to attract the wrong entities or insult the right ones.
In Kemetic Orthodoxy, natron is used before performing Senut, a ritual which brings the practitioner closer to Netjer or one or more of his forms. I will cover Senut more in depth at a later date. In this pre-ritual ritual, the practitioner takes a small amount of natron or natron water, and uses it to cleanse the whole body. In the case of a bathtub, a small amount about the size of a corn kernel is placed in the bath water and the person soaks in it while they wash with the water. In the case of a shower, they simply use the natron or natron water to scrub/cover their bodies and rinse it off.
The use of salt as a substitute is common when the person performing Senut is unable to use natron for any reason. Natron water can be bottled and used at a later date if the water is fresh. In cases of being away from home, this can be quite useful.
When using natron for purification, one should take measures to cleanse all of their body; mouth, arms, legs, reproductive parts and the end of the digestive tract (if you get my meaning). This is done so that the whole of the body is clean, including the less than nice parts. It is like showering before meeting family, going on a big date, or applying for a job. It is something nice and necessary for being in polite company.
How to Make Your Own:
Several websites offer to sell you natron, but like many sites involved with the occult, it is generally better to make it yourself and is less expensive to do so. Making natron is rather simple, but it can easily go wrong if you don't pay attention to the task. While making it is not completely true to tradition, it is the closest one can get outside of Egypt, and it keeps to the traditional elements of natron in the results. Follow the directions below.
First, gather salt and baking soda. Both of these can be found at your local market, but I recommend considering different kinds of both salt and baking soda. Those salts that come from the sea you may want to avoid as the results can have a fishy smell and are not entirely up to par with purity.
Combine equal parts in a large pot or pan, adding in water to act as a carrying/mixing agent for the two.
Put this on a medium heat until it comes to a boil. At this point, the mixture should be a syrup/molasses like consistency.
Turn off the heat, and pour the mixture into a cookie sheet. This should be spread fairly thin to allow the natron to dry.
Next, you can either pop the sheet into the oven for a few hours to dry, or you can leave it out where it is protected from bugs and dust for a few weeks as it dries.
Once dried, you will want to put your natron in an airtight container, as it can absorb moisture from the air if left in the open. Leaving it in an open container can also leave it open to picking up bugs and dust, though bugs will avoid natron as a general rule.
You should take the time to ensure your natron is dry before putting it away, as natron which is still wet can become moldy and musty, which defeats it's purpose.
Kemetic Orthodoxy's Beginners Class