Yes, I add rock dusts. Granite dusts for me. Though lava rock dust would be cool.
BTW here is a source if you want to play with a purchased product.
http://www.rockdustlocal.com/store.html
IMO you don't need a lot here. Just replacing trace elements. I add about a tsp per hole. That's it. I can't tell you "if it makes a difference." I have a whole slew of practices and have never done any scientific study where all factors are controlled for except for use of rock dust. Instead its just part of my healthy soil routine which includes:
1: Keep it covered with organic mulch.
2. Keep it chemical free
3. Encourage worms with compost and high amounts of organic matter.
4. No till.
5. Replace what is removed (trace minerals etc).
6. Crop rotation or soil resting.
7. Compaction prevention.
8. Interplanting
Stacy