"Good" pebbles should be just that, like pebbles, so they wouldn't stick to her.
My Honey likes her cardboard box with an entrance & an exit hole cut in, which she enlarges. And I don't use a cage at all, but an xpen instead, with a waterproof floor under it. I go sit on the floor in it when we visit. And if she's messy, like with her hay or pebbles, it's confined to a 4'x4' area.