Since you've got a slight spiral engraved into the hole already, I'd suggest using red LocTite on the perimeter of the plug instead of some sort of flexible sealer. That will assure that the plug stays snug, and doesn't leak.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
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