First, please know that there are no medicines or supplements clinically proven to 'clear tar' from your lungs. The excellent news is that your lungs have a highly effective, natural self-cleaning mechanism. The tiny cilia in your airways, previously paralysed by smoke, are now actively sweeping out debris. To support this natural healing process, stay well-hydrated to thin mucus, engage in regular cardiovascular exercise, and practice deep breathing. If you experience a productive cough, an over-the-counter expectorant like guaifenesin can help loosen mucus. Your body is already doing the hard work of healing!