It was a well known fact that Juuzou was made of lightning, similar to how a Hozuki is water, he is lightning. Due to this fact, even if Bocch somehow attempted to touch him he'd fail, not because he was untouchable or anything of the sort but because he'd vanish. Where could he have gone? The answer was Hirashin because Juuzou was also able to use this.
Unbeknownst to Bocch, Juuzou was able to listen to electrical sound waves that traverse the very air itself. In addition to his sensing abilities, this left him aware of Bocch's attack even if it wasn't almost immediately. Juuzou had used another form of Hiraishin and disappeared out of sight, leaving only his gold staff still in the air. As stated befofe, because he is lightning he also has the ability to travel through metal objects such as his staff. Even if Bocch attempted to touch him, he'd flow through the metal before he'd even realize.
After vanishing into his gold staff that should now be standing vertically right next to Bocch, his upper body would appear at the top of it with his lower still inside the staff. His hands would each stay at one side of Bocch's head, "10 Million.. 20 Million Volt Vari!" He'd release a surge of electrical energy onto Bocch as this all happened in the span of seconds.