I am not one to be daunted. Since Lily is smart (aren't they all?) I also know once she gets something she has got it.
Two things I did. I got a rag soaked in pigs urine and put it in her stall. No threat as she comes and goes at will. She went right up to the rag, smelled it, then when out and gazed to the pig field. This is good she is making an association and the smell did not bother her.
Next I found pig squeals on the internet - different kinds and played it to her. Oh yeah, now she has it. Especially when I found the right vocal. She went to her pig spot in the field looking for them more intently. And the sound bothered her. This is a good thing as I can desensitize her to sounds of squeals while she dines.
A little desensitizing at a time might be the answer with her. Then the only thing left is a relatively close encounter....I'll keep ya'll posted!