Yes it’s very important to clean the machine after every 4th bottle or when the clean funnel indicator light turns on. Unfortunately, formula can build up on the funnel during mixing because formula by nature likes to clump with water. If the formula builds up too much, it can affect how much formula drops from the powder container into the mixing funnel, affecting the machine’s accuracy. By removing the funnel after every 4th bottle and wiping the underside of the formula container, you can clean any formula build-up and ensure the machine works accurately. One suggestion to make cleaning easier is to purchase a spare funnel. That way, after every 4th bottle, you can remove the funnel that needs to be cleaned and insert your spare funnel that’s clean. Click here to shop for a spare funnel for the Baby Brezza Formula Pro Advanced.