False bottom in a jar?

Christina Ladd
by Christina Ladd
I have a blue glass jar I would like to use for dog treats, but I find it a bit too deep. I want to add something to the bottom to fill it, but what? I don't want to use clear pebbles since the crumbs of the dog treats will fall through the cracks, and it will make the jar difficult to clean. I'm looking for something I can pour in and it will harden, ideally clear so it is not visible through the glass. Anyone know of anything that fits the bill?
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