I've never heard of those, I'll look them up out of curiosity. Do you really only water them twice a year?
Yeah, pretty much. Or less even, adult plants can last for more than year with no water. Super easy to kill by over-watering, they will absorb it and burst like a balloon. I grow them right next to my high light orchids and I have to be careful not to spill. (<---mandatory orchid reference. :-)