The little mini hand mixer I use works so fast, and cleanup is a zip (just put it under the tap for about 1 second and zip it).
I use this for all of my hot drinks... microwave your 1 cup of water, add the packet, and then use this to whip it up in less than 10 seconds.
It also works for mixing the eggs and the creamy soups.
I love it.

www DOT ihealthtree DOT com/drink-mixer-ea-vitaminder.html