when you open a Ready Filter there is a picture of a giant gas can with a giant X through it so you know you cannot wash in gas. You can use the Ready Filters multiple times as long as you follow instructions and do not use gas to clean, read above.... simple green or a mild detergent cleans very well. Gas is a lazy mans method that is VERY BAD for ALL FILTERS. The Air Filters are a great product and so are the oil filters. Look bubba, I won't use anymore Ready Filters. I did not see any red X's when I opened the package. My motor is worth more than a $10 air filter to protect it anyway. I have been using gas to clean air filters for 15 years, and if a filter won't hold up to the way I do things, I won't buy it! Enough said, Ready Filters are crap in my opinion. Why don't you contribute something to this board before you bash me because I have an opinion.