This isn’t exactly the same, but wondered if it came up in your searches? Seems like a similar problem and there are lots of tips in the comments. Hope you find a solution!

https://toolguyd.com/how-to-remove-ultra-fine-aluminum-swarf-chips-slivers/

How deep is it? I’ve sterilized sewing needles, cleaned the area (alcohol), and gently dug into the surface skin to get to splinters more then once. Have a good pair of tweezers clean and ready to help. If it’s too deep have a medical professional look at it.

@Jilly Thank you for that link! I don't know why I didn't think to search "metal shards." My thumb looks exactly like that!

@maddielee They're extremely teeny-tiny specks embedded in my skin. Gorilla tape helped get a lot out/off (and hurt) but it's almost impossible now to see them just looking straight at it. I have to move my thumb side to side in the light to see them shimmer.

The pain is much better now after a day and a half. I can apply pressure to my thumb and not squeal. I'm definitely going to try some of the things in the link.

Thank y'all!

That was an interesting read, Jinx. As I was reading, I was waiting for someone to mention the bacon fat idea. A friend of mine taught me to wrap a piece of bacon around a finger with a splinter. It works! The finger swells and pushes enough of the splinter out so you can grab it with tweezers.

The Brazilian hair removal wax idea seems like it would work.