Cleaning fungus from a bansuri, which is a traditional Indian bamboo flute, requires gentle care to avoid damaging the instrument. Here’s a step-by-step guide:

1. Inspect the Bansuri:
   Before starting the cleaning process, carefully inspect the bansuri for any visible signs of fungus. Identify the affected areas and note the extent of the growth.
2. Remove Loose Debris:
   Gently tap the bansuri to remove any loose debris or particles that may be on the surface. Be cautious not to hit it too hard to avoid any damage.
3. Use a Soft Cloth:
   Dampen a soft cloth with a mild cleaning solution. You can create a mixture of equal parts water and isopropyl alcohol or a mild dish soap. Make sure the cloth is not too wet; it should be slightly damp.
4. Wipe the Surface:
   Gently wipe the affected areas with the damp cloth. Take care not to apply excessive pressure, and avoid getting the cleaning solution into the tone holes or any other openings.
5. Q-Tips for Detailing:
   For smaller and hard-to-reach areas, you can use cotton swabs (Q-tips) dipped in the cleaning solution. Be very gentle to avoid damaging delicate parts.
6. Let it Dry:
   After cleaning, allow the bansuri to air dry completely. Ensure that there is no residual moisture left on the instrument.
7. Use a Soft Brush:
   If there are areas where fungus has accumulated in crevices or on the bamboo surface, you can use a soft brush (such as a small paintbrush) to gently dislodge the fungus. Be very careful to avoid scratching the bamboo.
8. Sunlight Exposure:
   Sunlight can help prevent the growth of fungus. If possible, place the bansuri in indirect sunlight for a short period, ensuring that it is not exposed to extreme heat or direct sunlight for an extended time.
9. Storage:
   Store the bansuri in a cool, dry place when not in use. Consider using a soft case or cover to protect it from dust and humidity.
10. Repeat if Necessary:
    If the fungus persists, you may need to repeat the cleaning process. If the issue persists, it’s advisable to seek professional help from an instrument repair specialist or a bansuri maker.

Remember to handle the bansuri with care during the cleaning process to prevent any damage to the delicate bamboo. If you’re unsure or uncomfortable with the cleaning process, it’s recommended to consult with a professional instrument technician for assistance.