I've used it. Even wrote up a recipe with it.
http://www.e-cigarette-forum.com/forum/e-liquid-recipes/68612-good-n-plenty.html#post1415541
Careful, I'd only stopped smoking a few days before that recipe was posted and it's on the strong side. It's not nearly as strong as a mint oil, but I think that is due to them using fennel seeds instead of anise. As long as it is not cold, it mixes pretty well.
Yes, I've read the warnings on
vaping oils many times. Yes, I do and still vape oils, like anise and mints. No, I've never had any issues with my lungs. You might be able to do a search and find the post where Rolygate stated he had been
vaping DIY mix with a mint oil for 9 months straight and he had no lung issues either. If you look up the reported causes of lipoid pneumonia you'll find that the most common cause of this uncommon condition is inhalation of mineral oil, such as laxatives, then animal fats, and way down on the list is veggy oil like anise and mints. It is more common to fire eaters than any other demographic.
Is it safe? No. No flavorings are safe to inhale. Conduct yourself accordingly.
Me, I'm going to vape some blueberry muffin juice.