If you’ve purchased a reusable or washable cabin air filter, you can clean the filter in a few easy steps.
Use a hose with low-pressure water to rinse the filter from top to bottom,  allowing gravity to wash away the dirt. After you’ve rinsed the filter, fill a bucket or bin with soapy water, and totally submerge the filter for about 10 minutes. This gives the soap enough time to break down any tougher components and bacterial growths that may have gathered on the filter surface.
After it has soaked, rinse the filter with low-pressure water once again, making sure to get rid of any soapy remnants. If any soap dries on the filter, you may smell it for a little while once you have reinstalled it. Allow the filter to air dry before you reinstall it.