While inside his puppet Hiruko, Sasori summons two large torpedo-shaped containers. When opened, the two containers release thousands of Kunai that pierce into the target's body. Then, another set of kunai are loaded into the wooden cylinders attached to the containers. When opened, a full load of kunai with multiple explosive tags attached to each are shot to the ground near the target. They then detonate, causing a large explosion.
The name 'Jūhako' is probably meant to invoke the feeling of the word 'ohako' (十八番, favourite trick, speciality, Literally meaning: number eighteen), which is the word used to describe what Hiruko is to Sasori. The first kanji of this word can also be read as 'jū', creating 'jūhako'.