hi yellowtang, found this thread super interesting, and i hope you will catch ur 'devil', of course, hopefully no harm will come to it.. just to add on to your "Plan 1":
i find this very effective if you use "live food" inside the beta box.. the wriggling baits always tempts better than a dead one..
what i do is, use a transparent zip-lock bag to contain live brine shrimp, this way, the live brine will not flow out of the box, and yet it remains highly visible to your bellus..
next, put the zip-lock into your beta box, and wait..
this usually yields success once the curious fishes attempt to get the live brine.. and not wasting and live brine in the process..
hope that might help a little in case ur night ops fails.. GOOD LUCK!