Q: How do you clean a woven nylon strap?

Hi

Apple's recommended steps for cleaning and drying your Woven Nylon band are:

• Remove the band from your watch;
• Wipe down the band with a nonabrasive, lint-free cloth;
• If required, the cloth can be lightly dampened with fresh water;
• Allow the band to air dry.
  • Direct sunlight, high temperatures and humid conditions may cause damage.

More information:

Cleaning and wearing Apple Watch - Apple Support