@chai2,
Yeah, thought of the neti-users here when I read this.
Definitely boil your water before you use it! Don't use straight tap water!
(Wait until it's stopped boiling before you use it in the neti pot though. Protip.)
Edit: kosher salt works fine though, that's what we use (because it doesn't have iodine). A little baking soda helps soften things.