The ancient Egyptians harvested naturally occurring natron from dry saline lake beds and used it for all manner of hygienic and household purposes, as it holds cleansing, purifying, and preserving qualities. It was also an essential ingredient in the mummification process.
This natron was ritually cooked during the Hermanubis operation and left to dry throughout the night of the Mercury cazimi. The result is a salt blend which can be used to create ritual circles or barriers for containing necromantic operations, delineating boundaries for the dead, or used however else natron can be applied. It can be cut with other salts to make it go a longer way, via the principle of contamination.
1/2 oz glass vial with cork top for $13