That's a great idea! I've been using floor varnish as well, but brushed on as I don't really have a good space for shaking excess off etc. That bottle might actually also be useful for collecting some of the excess varnish again for reuse as well as you're probably going to use 3-4x more varnish than there will be on the mini in the end.
Need to give it a try someday. Though I first have to make sure the missus is away as I doubt she will find the idea as great as I do

The problems of not having a room completely for yourself...