A trick a friend of mine shown me that works like a charm, so put away the bleach and power washers. All you need is what is listed below, if you let the helmet soak in the water for a minute, it will require very little effort to get the results shown in the pictures. Scrub with the brush, rinse and do a final wipe down with the cloth. Leave to dry.
• Warm water
• Wash tub
• Soft bristled brush
• Wash cloth
• Laundry soap (Powder)
Please remember to read the manufactures directions for tips, etc.
Further cleaning will be required if in a suspected White nose area. Check this link out for more information: