Here is a good link with excellent information. https://the-chicken-chick.com/salpingitis-lash-eggs-in-backyard/
Great info there. From what I read, if you see a lash egg, that bird has already been infected for probably months. So there is no "catching it early" from the standpoint of treating a hen after you get a lash egg. Prognosis from that article is not good, I am afraid.
On a more practical note, and I hope I do not get flamed for this question, but if you have a chicken that passes a lash egg, can you still harvest the bird for meat or do you have to destroy the animal due to the infection? All my birds are dual purpose, and from the beginning I have planned to get eggs from them and then harvest them at some point.
To @jswilliams430, thank you for posting and I hope my question does not offend you or anyone else because I know lots of people here on BYC forums have chickens as pets. I am raising my flock for eggs and meat, so I look at this issue from that point of view.
There are a few YouTube videos on this subject and one of them has a treatment option of Oregano tea for the sick hen. She gives some special TLC to the sick hen but everyone in the flock is treated with the tea. I have no idea if that treatment is worth anything, but you could watch it and decide for yourself.