We did something similar to this a couple of weeks ago except we didnt use the q-tips, we just dropped a drop of the dish soap into the food colouring, same effect though. The kids loved it. We used homo milk and it worked just fine.
OMG! I remember this from college! I did it in a placement and had it in my resource file (which I threw out during my move). So going to do this with daycare kids when they're a little bit bigger. Thanks for the reminder of this great activity Reggio! I had completely forgotten about it.