I assume you don't have a scrotum to test for yourself, but oddly it wouldn't hurt at all.
The balls are ultra sensitive, but for some reason the scrote itself just laughs in the face of danger. You can pinch the shit out of it and feel nothing. Just pinching random arm skin hurts a lot quicker than pinching the ol ballsack. And stretching? Forget about it. That's the thing's whole job.
just keep the actual plumbing clear of the carnage
I don't think they're asking about the stretching, but about having a puddle of alcohol on your scrotum. That was my first thought as well. Probably okay if it's wine, but not sure about something high proof.
Oh, well, silly me then. No, like the other guy said, it's very stretchy. If you have your own scrotum, it's easily confirmed. If you have girly parts, the skin is very similar to the outer labia: very sensitive to scratching, but it doesn't hurt to stretch it.