Summarize:

After you have finished playing the dizi, use a soft cloth to wipe it dry. You may use a long rod to push a cloth inside the dizi to catch excess moisture. Cloth bags, plastic airtight bags, or hard-covered soft-lined cases are ideal containers in which to store a dizi. Bamboo flutes are susceptible to expanding or contracting depending on temperature and humidity. Do not place in direct sunlight such as on a windowsill, as this will likely lead to cracked bamboo. If you are taking the dizi outside on a cold day, allow the flute to acclimatize before playing it. Since moisture may gather in the dizi, even if you’ve dried it, fungus spores may start to grow. Use food grade hydrogen peroxide to spot clean the flute to eliminate fungus growth. Some flute owners choose to oil their dizis with almond oil 3-4 times per year. It is best to wait until the flute is completely free of moisture (i.e., waiting a day after playing and drying it) before applying oil. Use just a bit of oil and rub it into the dizi with a soft cloth. You may also choose to oil the inside of the flute as well. Allow to dry completely before playing.
Wipe the dizi dry after playing. Store the dizi in a dedicated case. Avoid swift temperature changes. Eliminate any growth of fungus. Periodically oil the dizi.