I was in the same predicament a few weeks back, i decided to get one in the end as I was too curious.
First off this thing is loads of fun in use. As you suspect it does throw out a bunch of chaos when you touch, when you release it hold the voltage it was at when you remove your finger. It also seems to be running at audio rates although you can slow down the modulations if you apply very light pressure but still their quite fast. Like traditional runglers you can’t control the clock rate or frequency of the oscillators inside (the way you touch seems to play its part in this area too).
The inner triangle of pads activate the runglers, you need to connect 1 inner to an outer pad to get it going if that makes sense. They seem to be cross modulating each other, touching an inner pad to different outer ones had different modulation flavours.
I have load of chaotic type samples ive recorded with it but as their working with other modules its hard to hear what the grassi is doing.
Here is a simple example: 1 of the 6 outs going into a sine wave volt per octave you can hear more clearly what its doing. Anywhere the pitch is sustained is where i release my finger toward the end i attempt to slow it down a bit touching lightly. 
https://soundcloud.com/macros/grasssi-sine-test-1
