I love Newton and own it as well, but you could save a lot of money just doing this by hand unless you plan to use Newton a lot more, which is highly probable.
Handmade technique would basically involve a bunch of randomly sized circles with an adjustment layer on the whole stack using a gaussian blur and matte choker to get the liquid sticky effect as the come in "contact" with each other. You could create a bunch of circle layers with a cool script called Array http://aescripts.com/array/ As far as random scalling them, there are a few ways you could do that. Array might have a way of doing it, but a random expression on the scale parameter would probably do just as well. I'm not sure exactly what the expression would be, but I'm sure someone's written one up here on the cow. Once you get all your circles created, basically animate them on, then animate them off. You can offset the layers to get a bit of randomness with the motion using this script - http://aescripts.com/layer-random-shifter/ Make sure you do your animation before offsetting the layers. You could also employ Ease & Whiz bounce to get some bounce in the water http://aescripts.com/ease-and-wizz/
Hope that helps with some additional methods. Don't get me wrong, tho, Newton is freaking awesome.