1. Laundry Sink or Bathtub
2. Gentle Laundry Soap (i.e. Woolite)
3. Towels (2)
Time: 15-30 minutes to wash, 24-72 hours to dry.
Step 1 - Remove the visor
Step 2 - Place towel in tub
You do not want to scratch your nice helmet, do you? Make sure you put the drain plug in first.
Step 3 - Measure out some of your favorite delicate laundry detergent
Step 4 - Fill the tub
Step 5 - Wash the helmet
Squish the soapy water through the pads and the rest of the helmet. Open your vents and let some soap drain through them as well.
Step 6 - Drain
Step 7 - Rinse
Rinse the soap from the outside, vents, and inside. To get the soap out of the pads, squish the clean water in them repeatedly. Be thorough
Step 8 - Drain
Hold it like this for a bit to let much of the water drain out.
Step 9 - Dry
The best for way for a helmet to dry is on a dish rack like this one. It allows air to circulate to let it dry faster.
Sumber : http://www.sportbikeguy.com/garage/floor/lid-inside-clean.html