Rinsing
Soak for 15 minutes in cold water – you can add a period underwear detergent tablet to the soaking water if you wish. Gently squeeze out the blood. Repeat as needed until the water runs clear.
Washing
Machine or hand wash in cold to lukewarm water (avoid hot water at all costs).
Use a mild, biodegradable soap, ideally fragrance-free.
Do not use oil-based products (some stain remover bars for example), because in the long term, the oil seals the fabric fiber and affects its absorption capacity.
Drying
Dry flat or hang outside.
The dryer should be avoided as much as possible, although it may be desirable to finish drying in a machine at a low temperature for about fifteen minutes to eliminate any remaining moisture (the latter is the worst enemy of bad odors).
Sharing (optional)
Dig a hole in the ground and pour the water from rinsing your underwear at the foot of a tree, in your garden or in the pots of your houseplants.
Dig the hole well and cover it with soil once you have made your offering.