Micro Mesh can be washed and dried... or it can just be kept soaking in a pan of water (or naphtha), and used moist. It's not so much 'wet sanding' where the liquid carries off the waste. I just find that MM works better when soaked before use. Since it doesn't seem to degrade with soaking, I leave the material in a pan of water for days at a time. MM isn't a simple abrasive. It's a fairly engineered product. Is it best to use Micro-Mesh wet or dry? "If possible, it is always better to use a lubricant. This will extend the life of the MICRO-MESH™ greatly and keep the material from loading. It will also keep heat generation to a minimum. There are many types of lubricants, but generally water is best. It is best to work using a light mist or spray. Flooding the work surface or work piece is not recommended as it will cause the abrasive to skate across the surface, making less contact and removing less material."