That's how my demo is slated: female voice at the beginning. Not very pro for opposite sex slating. Then again, I guess I can understand why some would do it that way. Guess I'm undecided but leaning towards "against."
I don't advocate a slate on your demo. That was a very 80s demo thing. Demos were also longer in the 80s. Today you have a one minute demo. The listener will give you 4-10 seconds to wow em, and it's really closer to 4. To give up valuable real estate on your demo to slate your name takes away from the opportunity to sell your VO brand. Using someone of the opposite sex takes you completely out of the equation on your own demo. If the buyer is listening to an mp3 they can see on the file who you are. If they are listening from your website it's obvious who you are. If they put in your CD you should have a label/packaging for them to know who you are. No need for a slate.