I agree with Clay. Just use a liquid detergent and just wring it out. It will swell until it fully dries. This is not something you want so do on race day because it can take a few hours for the filter to completely dry. Best to attach it to the front of a fan to make sure all the moisture is removed. Back flow from the carb will keep the filter lubricated. Clean the filter often to maximize performance we do it after each race.