One box of cleaning tablets should last for about 6 weeks of cleaning your Heatwave Milk Warmer. This product has been tested with the Heatwave to help break down the milk residue in the lines. It is important to clean your Heatwave Milk Machine once a day. Thankfully cleaning the Heatwave is a quick and easy task and with this cleaner it can be even quicker as you can premix the solution and use it for a week.