Great post pixielolz , I might try this out if we can find a strong enough container that'll take some abuse :)
My kids love sensory toys like these but we also have issues with pica (eating everything but food) and chewing everything so its always kinda risky..
Yeah, you would need something durable. I'm sure you can find something that will fit your needs.
I was about to suggest water pearls, as tactile sensory toy. But the pica part makes that not a good choice I would think. Though, you could always put them in clear bottles/containers, partly filled with water. But then your left with a visual toy again.