Yep each compartment is sealed hard and contains water, so they explode with quite a bang when put on the barbie!
And that reminds me, my wife (who's chinese) tells me you can drink the water inside, and that its pure water. Good too know if you run out of the stuff or get lost in a jungle.
I found cutting it to be a real PITA. Its always pinching the bar, there's usually so many of the sticks its a huge time waster, and dangerous too as its so easy to get a kick out of it. I'd recommend getting a dozer instead if its a large area.