Liquid Dirt Remover Formulated to quickly cut through Liquid Power, loosen the dirt, and flush your filter clean. Will not harden or damage filter foam like solvents and gas. Must be washed from filter with soap and water. Liquid BIO Dirt Remover :: Biodegradable Air Filter Cleaner Clean your BIO Liquid Power-oiled filter with Liquid Bio Dirt Remover. Using a washing machine or hand wash your filter in a bucket-this granular water-soluble cleaner can go right down the drain without clogging or harming the environment. Unlike solvents or gas, Liquid Bio Cleaner will not harden or damage the filter foam.