"Do not touch water"
This is a practice where the mother avoid making any contact with water over the confinement period. Instead of using water on its own, various herbs are boiled in water to create solutions for cleaning and hydration.
This ritual may sound extreme. But in the era before treated tap water was available, water retrieved from rivers and wells could be infested with various water borne diseases. Therefore, the avoidance of these untreated water had protected mothers living in these environments.
Because tap water is reliably treated and easily accessible to us today, the practice of avoiding water is no longer required. Mothers may still choose to prepare various types of herbal solutions for drinking or cleaning for various reasons. But in modern Western medical and Chinese medical understanding, mothers can and safely touch and use tap water during the confinement period.
So, this practice of avoiding (untreated) water has an important role in some context, but is no longer applicable to us with access to clean, treated tap water.