Fei Kong Hua Shui Shen You Guan (飛空滑水神油罐)

Drawing of Fei Kong Hua Shui Shen You Guan, from 'Wu Bei Zhi (《武備志》)'.

Fei Kong Hua Shui Shen You Guan (飛空滑水神油罐, lit. 'Flying slippery water divine oil jar'), despite the fancy name, is simply a ceramic jar filled with a mixture of egg white and tung oil. It is a "hand grenade" designed for naval warfare. When thrown into enemy warship, the jar breaks on impact and spills its content, turning the ship deck dangerously slippery. Furthermore, the mixture catch fire easily due to its tung oil content.