I’ve used Magic Worm bedding in the past with good success. it’s peat moss, that you add just a little water too to get some moisture. worms stay clean. I’d not use dirt. Jack
This is the kit I bought a few years ago. I replace the bedding each year. It works awesome. I think I got it at Fleet Farm. I believe the bedding sells for about 5 bucks.
I’ve used both the Frabill and the Buss bedding with good success. I think the keys are the amount of moisture (don’t make it too wet) and the temperature you keep them at (40-45 degrees works great)