West Marine Bowl & Drain Cleaner uses powerful natural enzymes to remove tough stains and eliminate odour without harming plastic, fibreglass or porcelain heads or drains. The eco-friendly, phosphate free formula is compatible with all head chemicals and pump out stations. It does not contain blech, acids or other harsh chemicals. In addition to deodorising and cleaning marine and RV heads, it lubricates head mechanisms to keep sanitation systems functioning at their best. Safe for year-round use or as preparation for winter lay-up.