The name
Kohelepelepe is explicit, and the story explains it. The pig demigod Kamapuaʻa was pursuing Pele. Kapo, Pele's sister, detached her own genitals and threw them to draw him off; they landed here and left the imprint that is the crater.
The name is not a euphemism and was not treated as indelicate. Hawaiian place naming records what happened, including this.
Koko Crater
The English name comes from Koko Head nearby, koko meaning blood, for the reddish soil. The crater holds a botanical garden, and the old military tramway up its side has become one of the most-used stair climbs in Hawaiʻi.