purifying salt (thrown before a sumo bout)
Specifically the salt thrown by a sumo wrestler into the ring to purify it before a match. The term is strongly associated with sumo culture.
The sumo wrestler throws purifying salt into the ring.
Compound of 清め (purification, nominal form of 清める) + の (possessive particle) + 塩 (salt). The practice originates from Shinto purification rituals.