Confession, you are correct, they are officially called "nursing rooms".
Furthermore JW parents go far beyond simply "spanking"... I'm sure everyone has stories of having items thrown at their heads, being beaten on the head, in the face, on the back, whichever body part happened to be convenient, by enraged parents, being struck with a variety of household implements, etc etc. There's corporeal punishment - spanking, and then there's just furious parents beating the shit out of their kids for the most trivial of reasons.
Just look at this guy in the article, he was actually knocked unconscious on more than one occasion.