You don't need a priority skill, you need to be employed in a critical sector. Example, I know a tradie plumber that found a job offer (used a head hunter) working for Liebher in the mines out in WA (mining is critical sector). He applied for an exemption, had his visa approved and has been out there since Jan. I'm looking for companies who have contracts in a critical sector then will use lawyers ($1500) to apply for my exemption. Finding a legitimate job offer and employers that will consider you is difficult, I have already handed out my CV to +500 employers and have resorted to calling them directly. I have had a few solid leads thus far, and you must be able to sell yourself, your current position, etc.
There's evidence on travel exemption forums all over FB doing the same thing, but it's no easy feat. They also help outline which documents home affairs will require from you to successfully apply for an exemption. I personally, have decided to use lawyers to help dot my T's and cross my I's. To each their own.