This is something I've never worried about since open fermentation was practiced for millenia and even still today by a few large breweries. Also if your airlock is not bubbling it doesn't mean anything. Just that it's not bubbling. Not a way to measure fermentation.
"Look, let me explain something to you. I'm not Mr. Lebowski. You're Mr. Lebowski. I'm the Dude. So that's what you call me. That or His Dudeness... Duder... or El Duderino, if, you know, you're not into the whole brevity thing." -The Dude