We have a Baja step which has a hole for an umbrella on it. The umbrella pole is too small and so the umbrella wobbles around quite a bit. What can I put in the hole to make the umbrella stable? I found umbrella rings that work for tables,to protect the table from scratching. Would that same sort of ring work to stabilize an umbrella on a Baja step? Or is there something else that would work better?