Currently, muffin fans, like you find in computer power supplies and mounted in computer cases as well as other electronic gear, are manufactured in a manner that makes them unserviceable. They eventually get fouled with dust and other airborne particulates which cause the fan to "gum up" and stop working. If they could be cleaned, their lifetime would be considerably longer. If you try to take one apart they simply break. If you try to clean them by soaking in even with the most exotic...