You fill the bottom tray (the one without holes) with water and then put the other tray on top it and the excess water comes thru those little holes.
BTW, I see a couple of entrepreneurs have some up for sale on eBay.
So... I am finally getting around to trying them tonight. First with some OGD BIB. It is a bit watered down, and deteriorated the finish that I love from OGD. However, afterwards I poured some current GTS over an ice ball, and voila! Me likey.
While the balls are great, an easier way to make a single, big ice cube is cut off the bottom of a plastic water bottle and use that as a mold. Pick a bottle that's just a little smaller than the glass you want to use. Similar effect, but a lot easier to make.
Aha, hints from Heloise!
For bigger balls, use a water balloon in a large cup.
I had seen these online last summer and really wanted them, but the molds were a bit too pricey for me to bite. I was so pumped when I got these in the mail after Christmas! I have already used them several times, and they are nice. While I usually drink my bourbon (and other whisky for that matter) neat, it is nice to have this option that minimized dillution.
Just got mine in the mail today, gotta love that they send this stuff all the way down under!
I never got one. They sound pretty neat though. I guess I'll turn in my ambassadorship.