Here is a question I asked Dr. David Ghodoussi of Optimum about the preferred media of use for ONR.
3A. - What are the finer points of reasoning on the ONR directions stating to use a MF towel rather then a wash mitt or other media? I prefer using an MF towel but would like to know the reasoning behind that being specifically stated.
The reason we recommend Microfiber towels is that there are anywhere from 50,000 pores per square inch for an average microfiber to 200,000 pores per square inch for a very plush Microfiber towel. These pores are active sites to trap dirt and remove it from the surface. Therefore you get a much greater cleaning and protecting effect from a microfiber towel than a wool mitt, etc. The towels we offer are on the upper end of the range I mentioned. The only draw back when using a Microfiber towel as the wash media is that it is hard to remove the dirt that is trapped by No Rinse from the towel unless you use a strong detergent like Power Clean.
Another great wash media is a soft sponge (minimum 80 PPI) that works great for washing with No Rinse. The advantages of sponge over Microfiber is that dirt particles can get adsorbed into the sponge and away from the surface. We are working with a foam manufacturer to develop a mitt that not only is safe and gentle for the automotive paint but also has good cleaning and dirt release properties. Once we complete all the testing and development, we will make this new foam mitt available to help make the wash process with Optimum No Rinse easier.