This is one of the weird things he (my stepdad) actually did when we were kids…
So he would grab and egg and if we were sick, he would rub us down with alcohol and then rub us down with the egg wherever it was aching/hurting… focused on that one spot. So like for a headache, a stomachache, or if they had a leg injury—like issues where they couldn’t walk, and then he also had sage and a lot of other plants (that’s the only one I can remember by name), that he would burn, so it was kind of like incense and the smoke from that would also be spread over your hair and body. It was an actual like clump or branch, not small—but a bundle of sage, yerbabuena (I don’t know what the name of the plant is in English, but it translates from Spanish into “good herb”) and a few others. He would get a glass, usually like a taller glass, so you could see the different densities of the egg, and the cloud—the whites, and… depending on the shape of that, he could see what made you sick, like he would “read” it. I told him people did that during the Salem witch trails and died for it, but he really (thought) he could read it.
How did you come across this folklore: “I refer to these as “sketchy stories from my (step)father/sketchy things he did when I was a kid…”
Other information: “My dad has a lot of stories like these, but my mom was big on not sharing them, or letting us hear them—so I heard this in my teens, when were allowed (finally) to ask and he would actually answer… my mom said it would invite bad people/things to us or something…”
The healing comes from the idea that the egg will absorb the pain/sickness, which will then be transferred into the contents of the egg, and then be revealed in the glass to tell a reader the source of the pain/sickness. There are a number of groups that link eggs and healing, especially by way of transference. Folk medicine, although not based on any empirical scientific evidence, can still be effective, which is why many traditional practices are still practiced.