Get bombed and simply walk backstage through the entrance curtain. I've done this about a dozen times and I'm surprised at how well received I always am back there. So long as you stay positive, you won't get kicked out. It will enhance your experience. Optional: demand they give you a liability waiver to sign and try to get yourself booked on that very show. I've come close to pulling this off, but the best I got is a promise to be booked on the next show. (He knew I could draw twelve people, which would've made me his top guy. He texted me about it afterwards but I ignored him because I wasn't the same drunken dipshit I was when I met him.)