Buzz
The bamboo tube serves as a barrier, restraining the bloodlust of the demoness Nezuko. However, it doesn't completely nullify her fierceness towards humans and their blood. This is likely attributed to Nezuko's strong will and the efforts of Master Urodokai in enchanting her. The master instilled in her the belief that all humans are her family, compelling her to protect them at all costs.
Even with the use of enchantment, why does Nezuko still need to wear this bamboo tube? Upon reflection, it proves somewhat cumbersome in her daily activities.
While the bamboo tube doesn't play a significant role in controlling the temperament of the demon Nezuko, it does mitigate certain risks. For instance, if she accidentally licks human blood, it could lead to a loss of control and a surge of rage.
The bamboo tube functions as a backup protective measure, concealing the fangs - a distinctive feature of demons - and presenting a gentler appearance for the character. It is also advantageous for Nezuko when appearing in a human-like form to aid in their protection and blend in. The Demon Slayer Corps, especially the Pillars, vehemently oppose the presence of demons within the organization. However, Nezuko's mild demeanor and her ability to restrain herself have given her a chance to stand side by side with her brother. Her presence offers a fresh perspective on demons, instilling hope that they can control their bloodthirst with effort or at least regulate their cannibalistic urges in some way.
