Wikipedia
Nyobeng
The Nyobeng is an ancient Dayak headhunting ritual that was performed to show gratitude for peace and good harvests. The ritual involved bathing or cleaning the skulls of sacrificed humans. The ceremony was performed by the Dayak Nyobeng Bidayu, Sebujit Hamlet, Village Hlibuei, Subdistrict Siding, Bengkayang and West Kalimantan, Indonesia. It was abandoned in 1894.