Scouting Resources - Camping - Tents. So, what if someone has an accident in your tent. What do you do? Well, apparently, you can wash these, just make sure to use a non-detergent soap. You can get this as Nikwax Techwash which is non-detergent and won't destroy the waterproofing.
Now what do you do about your thermarest's? Can't wash these, so "Thermarest":http://www.cascadedesigns.com/customer_service/faqs.asp?Action=ThermaRest#clean recommends that ou use soap, water and a soft bristle. For tough stains use Citrasolv (citrus-based degreaser).