In most cases, you can blend different flavours one after the other as very little residue is left on the auger and in the mixing bowl.  However, in some cases between strong flavours, a simple rinse is done by holding  a container of water under the mixing bowl while pressing the green button for approximately 3-4 seconds (Fig. 1).  The water is sucked up into the bowl and runs out once the green button is released (Fig. 2).