Dave Grohl recently revealed that his secret to healthy vocal cords is drinking beer and whiskey before a concert, but at Foo Fighters ‘ intimate pop-up show at New York City’s Irving Plaza on Thursday night, the frontman admitted it was all a “lie.” Earlier this month, Grohl told Dish Podcast , “[My doctor said,] ‘Well, what do you do before a gig?’ I said, ’Honestly? An hour before the show, I’ll open a beer and I’ll start drinking the beer. I might take an Advil because my knees hurt, my ankles hurt — whatever, I’m old. Then I’ll have a shot of whiskey. And then once the beer is done, I’ll open another beer. Then we’ll maybe have a group shot of whiskey, which we call ‘band prayer.’ Then someone will say “15 minutes” and I open one more beer and have one more shot and then hit the stage.’ And my doctor said, ‘Just don’t change what you’re doing.…