Niddah 62 - Seven Cleansing Agents
When a garment has the blood of niddah on it, it becomes ritually impure. If it may come in contact with ritually pure foods, it requires immersion in a mikveh. Prior to this immersion, however, one must nullify the blood by rubbing it with seven cleansing agents. If it was indeed blood, it will be removed or it will fade out, and if it was some kind of a dye, it will stay, but dye is not a source of ritual impurity and thus is not a problem. If he does not nullify the blood, immersing it in the mikveh does not help, since the impurity of a stain remains.
The seven agents are saliva (spit before one ate anything in the morning), split bean water, urine (left for three days), alum (sodium carbonate), aloe, detergent (possibly, saltwort), and ashlag. What is ashlag? Shmuel said, "I asked all seafarers, and that said that it is found in the crevices of pearls, and is removed with an iron nail."
All cleansing agents have to be applied in the order listed, or else the test is inconclusive. If he applied them out of sequence, or all seven simultaneously, he has not accomplished anything.
Art: Pierre Auguste Renoir - Aloe in Algiers Landscape