If you have a filter that cannot be washed, such as filter tips for smoking, you can clean them by gently tapping them against a hard surface to dislodge any debris. You can also use a soft-bristled brush, like a toothbrush, to gently sweep away any dirt or debris. Avoid using water or any liquids, as this can damage the filter and affect its effectiveness. If the filter tips are extremely dirty or clogged, it's best to replace them with new ones.