I’m a bit torn on this one. On one hand I’m always up for some creative DIY and concrete is a surprisingly unappreciated material. On the other hand, most of the types I’ve worked with are subject to grit and crumbling under this sort of wear and tear. I’d be a little wary of the resulting material contaminating my herbs, spices and grains.
Still, perhaps some clever soul know more. A special sealant or type of concrete which addresses these concerns?