I can't from this whether you are asking an honest question or if you can't google "define:serviceable", or can't google "corn whiskey" and see the first result in either case.
I'm suggesting that there probably is a product called "30 day old corn whiskey" and that it probably isn't very good.
You are entitled to that opinion, but you've missed the point entirely.
Whiskey fresh out of the still ("white dog") is pretty rough. Whiskey with 30 days of attentive oaking isn't awful (I'll happily get fucked up on it), 90 days will be pretty decent.