The park solution we used at the Canyon country build party was Duracoats blend bought from Midway. Just added steel wool to darken. That stuff works fast and is not sensitive to temp. It's usually done in 10 min. Temp. range can be from 150-200 degrees with 175 being best.
Here's a pic. Top rifle was parked with Pat's mix. Bottom rifle wth Duracoat blend.
The problem with parking at a build party is the time. You can't leave parts in for long periods of time. It will slow things down. Also, getting it to, and keeping it at 200 degrees per Pat's instructions will use up precious propane. Good luck with the park, and let me know how it goes.