You could try calling it Curing Salt?
Go to a meat market and ask them where you could find it.
This reminds me of my quest to buy Large Pearl Tapioca last summer. I went to six stores before I found it. Every single store employee would lead me to the instant tapioca pudding even after I would say, "I don't want instant tapioca pudding."
I just googled it to see if there was a mail order place. AmericanSpice.com has it.