The core and coverstock on the SP are simply too strong to be used as a dry lane ball. It takes well to a little shine to help it get down the lane, but to slap a whole bunch of polish on it, or drill it very weak, would go against its nature (strong solid particle), IMHO.
If you ever see medium/heavy oil, and you don't have a ball for that, I would drill and prep the new SP to be useful on more oil than the "old" one, not less oil.
If you never see more oil than what you are using the "old" SP for, then just keep it as a backup for when the first one dies, or is permanently injured.
--------------------
seadrive
Cogito ergo bowl