The main difference between the Clean and Multi is the convenience aspect. Many people don't have the time to Melt &  Mix. We have listened to our customers and now we offer the same great cleaner, still concentrated, but liquified and ready to go. PS MULTI is a completely different formula than PS CLEAN. With PS MULTI, we have improved the cleaning power with the latest in green cleaning technology. Also different formulas sit at room temperature in different states (liquid or solid). PS MULTI is a different cleaner than PS CLEAN and we have chosen a new formula that will stay in a liquid state in room temperature. "Just like coconut oil vs olive oil, both are fats but in different states at room temperature."