I purchased a used Coleman 24’ x 52” pool and want to hook to a sand filter and skimmer. There are two small rubber nipples that are in the side of the pool, I believe they’re for the skimmer. I am going to install a Hayward skimmer and need to close these two small rubber inlets permanently. Anyone have any ideas on what to use to plug them? They are soft rubber so they will be able to be clamped.