To conclude an ikki, a rite called Ichimi Shinsui (one taste of the gods' water) would be held, during which the members would make a written and spoken vow, after which they would drink, before the gods, the ashes of the document in which they had written their declaration and the penalties to which they would be subject should they fail to honor the ikki.
一揆の盟約を結ぶに際しては、神前で宣言内容や罰則などを記す起請文を書いて誓約を行い、紙を焼いた灰を飲む一味神水と呼ばれる儀式が行われた。