If you live near a body of water you can pick up some driftwood. It's often well-cured and without bark already, so all you have to do is pop it in the oven for a bit to sanitize, and maybe sand down any particularly sharp edges. Easy to replace, too, if it gets soiled. I have a couple of nicer pieces that I found that I coated in polyurethane to make cleaning easier. If you go this route just be certain to give the poly a week or so to cure, until there's absolutely no smell.