There isn't an NCT group near me so I've never been to one, but I have offered to give talks/do demos at SureStart groups and toddler groups, all of which have been declined. The toddler groups made the point that most of the mums weren't pregnant and probably not interested in cloth, but how are people supposed to find out about these things if they're not given the opportunity? And many of the mum's have under ones, and some are pregnant or will be in the near future. I also asked to put up posters in local health centres, doctor's surgeries, the hospital, library etc, but they wouldn't put them up because I had "nappy agent" on the poster which implied I made money from it.
I tend to just put woollies on Molly when we go to groups and when someone comments on her "lovely trousers" I mention that they go over her cloth nappies, dig a Goodmama/WN pocket/Blueberry out of my bag and mention I can do demo's if she's interested
It only worked once though