We went through this with dd and when I think about it, I still get that "I'm about to hurl" feeling. And I'm really not that queasy. When I tried to talk about it with her at the time, she picked out a really good, put it in her mouth, looked right at me and went "mmmm." It was soooooooooo bad.
It went on for a while, but she doesn't do it now. And FTR, dd is almost never sick, either. Im not sure if it was worth it. Really, I'm not. But it stopped, without any other intervention than us saying we could.not.stand.it. and walking away from her. It was an involuntary reaction. Honestly, I'm really not sure why it bothered me so very much. I'm normally okay with body secretions, even cleaning them up.