I was hanging out with my friend yesterday who is a stuntwoman too and she got a call from her agent about a commercial audition for Friday. I immediately called my agent to see if she submitted me for the job. My agent told me that I wasn't signed with them when they put out the notice for the job. She said I can just try and show up and see if I can "sneak" in unnoticed. Most the time there is a list of people who are scheduled to come to the audition but sometimes there isn't. I figured I had nothing to lose by just showing up, so I did. Fortunately they didn't have anything formal and no list of names so I added my name on the sign in sheet and they called my name and I auditioned.
The friend that told me about the audition said she actually booked a commercial by sneaking in. This happens a lot and sometimes it pays off and other times it doesn't. I just say knock on as many doors as I can and the right ones will open. It was fun.