Tonar told me about a finish for Swamp Ash that's pretty unique, and even gave the details on how to do it. Then, I recently saw a video on doing it. Basically, you end up with "negative" grain. You'd think I could remember what it's called, but I don't and can't find the details now. But, in the end, instead of having dark streaks of grain in a light or transparent finish as is commonly done, you end up with light streaks of grain with a dark finish. It's usually done with black and white, but I could see how you could do it with other colors, like this...
I remember now - it's called "Doghair". The shot above is done on Mahogany, but I've seen it on Swamp Ash.
Here's the thread where Tonar tells how to do it.
Here are a few other "reversed grain" Swamp Ash ideas; I doubt it's the same process - I don't know how it's done...
Turns out these techniques are collectively called "cerused", and it's commonly done with oak. I'll leave it to you to feed Google with that word. Spoiler alert: you'll end up on a lotta furniture finisher sites.