I haven't had to use one yet, but I made one to play with. The plastic is from an old political sign and is the same material that Brushy Mountain sells to slide in the bottom of the screened bottom board. The openings are too small for the bees to get in. I did make one modification that I will try if I need to use it. In stead of stapling the trap to the bottom board, I cut a clothes hanger to the proper length, ran it through one of the openings in the plastic board and bent the end to form a hook which fit in another opening in the rear of the plastic board. This should let me slide the trap into the hive toward the back of the bottom board, and pull it out as needed. If the bees glue the whole mess to the bottom, all bets are off on the usefulness of my modification.
Being on dialup, I can't watch the video. Reading the post's, I'm pretty sure of what you are talking about though. A square of sign board filled with borax and sealed up with crisco. I used it last fall on a hive that had beetles pretty bad. I stapled it to the inside of the top cover, just had to remember to lift the cover up level so the borax didn't dump in the hive. It did work. The number of visable beetles fell way down. However, when removed, their numbers increased again. That hives salvation was moving it out of the nice cool shady spot it was in for 3/4's of the day to full blasting Fl. sun.
Just because we kill the ones in the hive doesn't mean they are gone. They are out there lurking and breeding in the woods just waiting to get a whiff of a bees alarm phermone so they can find a hive. At this point we can only partially control the ones that get in our hives, hopefully, before they lay in them.