I know this may be radical, but what if you just don't tell anyone that you're going on vacation? Or where you're going? Even if someone hears you're going out of town, you don't have to give them any details, do you? You can say, "Yeah, we've never been to Cancun, so we're taking a week off and going there. We want to see some of the Mayan ruins and get in some scuba diving."
What could they possibly say except, "Have fun!" If they're the kind of people who think demons will come screaming out of the skull walls, would they dare counsel you about it? Even if they did, you can say, "Hmmm...never thought about that. Okay, we'll skip the Mayan ruins and go out on a pirate cruise and buffet. Yo, ho, yo ho, and all that!"