Your manual should explain what you need to do. Prefiring empty is usually recommended so that your elements can form a protective coating of aluminum oxide. After that kiln wash the bottom of your kiln and your shelf and start fusing. 🙂
I think I’m one of the few that uses that product on stainless! I don’t think there’s any set number of firings. I just clean the mold and recoat when it looks a little bare.
By the way, you can skip the 20 minute firing at 200. Totally not necessary.