Is it safe to ingest essential oils?

Someone’s trying to sell me on the idea that lemongrass and eucalyptus essential oils are some kind of miracle cure. They’re telling me to just drop a few drops onto a spoonful of sugar and eat it every single day.
I’ve never heard of anyone actually swallowing essential oils, so I’m wondering if this is total nonsense or if there's any truth to it. Is it actually fine, or is it dangerous? Personally, I think these oils are incredibly potent—borderline corrosive. My sister once had a couple of drops spill on her shoe and they practically ate right through the material...

That’s just nonsense.
It might pass if you use those synthetic oils most big-box retailers peddle as the real thing, but with pure essential oils? No way...

Look, those cheap essential oils you find at the drugstore—the ones that are basically just synthetic fragrances in a fancy bottle—should never, ever be taken orally. Period. Now, some actual pure essential oils can be used that way, but only if you're under the strict supervision of a medical professional. Otherwise, don't even think about it.

Someone’s trying to convince me that lemongrass and eucalyptus essential oils are medicinal, suggesting I just drop a few drops into a spoonful of sugar and eat it every day.
I’ve never heard of anyone taking essential oils orally, so I’m wondering if this is total nonsense or actually safe. To me, these oils seem incredibly potent—almost corrosive. My sister once dropped a few drops on her shoe and they actually ate right through the material.

Applying essential oils directly to your skin is generally a no-go, let alone swallowing them. Aside from lavender or maybe a couple of others used for minor scrapes, you really shouldn't. Most oils need to be diluted with a carrier oil before they touch your skin.
If you want to take herbal extracts orally, stick to tinctures.